List of acronyms: M

This list contains acronyms, initialisms, and pseudo-blends  that begin with the letter M.

For the purposes of this list:

• acronym = an abbreviation pronounced as if it were a word, e.g., SARS = severe acute respiratory syndrome, pronounced to rhyme with cars
• initialism = an abbreviation pronounced wholly or partly using the names of its constituent letters, e.g., CD = compact disc, pronounced cee dee
• pseudo-blend = an abbreviation whose extra or omitted letters mean that it cannot stand as a true acronym, initialism, or portmanteau (a word formed by combining two or more words).

(a) = acronym, e.g.: SARS – (a) Severe acute respiratory syndrome

(i) = initialism, e.g.: CD – (i) Compact disc

(p) = pseudo-blend, e.g.: UNIFEM – (p) United Nations Development Fund for Women

(s) = symbol (none of the above, representing and pronounced as something else; for example: MHz – Megahertz)

(Main list of acronyms)

• m – (s) Metre – Milli
• M – (s) Mega- – One thousand (in Roman numerals)

MA

• mA – (s) Milliampere
• Ma – (s) Megaannum
• MA
  • (s) Madagascar (FIPS 10-4 country code)
  • (i) Marijuana Anonymous
  • (i) Master of Arts
  • Massachusetts (postal symbol)
  • Megaampere
  • Morocco (ISO 3166 digram)
• MAA – (i) Mathematical Association of America
• MAAC – (a) Metro Atlantic Athletic Conference
• MAC
  • (s) Macau (ISO 3166 trigram)
  • (a) U.S. Military Airlift Command (1966–1992)
  • Mid-American Conference
• MACA – (i) Military Aid to the Civil Authorities
• MACE – (a) Multi-Agent Computing Environment
• MACHO – (p) MAssive Compact Halo Object
• MAD
  • (a) Magnetic Anomaly Detector
  • (s) Moroccan dirham (ISO 4217 currency code)
  • (a) Mutual Assured Destruction
• MADD
  • (a) Mothers Against Drunk Driving
  • MyoAdenylate Deaminase Deficiency
  • (p) Multiply–Add
• MAF – (i) Maintenance Action Form
• MAFF - (a) Ministry of Agriculture, Forestry and Fisheries (various countries)
• MAGIC – (a) Major Atmospheric Gamma-ray Imaging Cherenkov (telescope)
• MAGNETAR – (p) Metaprogrammable AGent NETwork ARchitecture
• MAGTF – (i) Marine Air-Ground Task Force
• mah – (s) Marshallese language (ISO 639-2 code)
• Mahasz – (p) Magyar Hanglemezkiadók Szövetsége (Hungarian, "Association of Hungarian Record Companies")
• mal – (s) Malayalam language (ISO 639-2 code)
• MALD – (a) Miniature Air-Launched Decoy
• MANPADS – (p) MAN-Portable Air Defence System
• MANPRINT – (p) MANpower and PeRsonnel INTegration
• MAO
  • (i/a) Molėtų astronomijos observatorija (Moletai Astronomical Observatory)
  • (p) MonoAmine Oxidase
• MAOI – (p) Monoamine oxidase inhibitor
• MAPS – (a) Monitoring Avian Productivity and Survivorship
• MAQS – (a) Museum of the American Quilter's Society ("max")
• mar – (s) Marathi language (ISO 639-2 code)
• MAR – (s) Morocco (ISO 3166 trigram)
• MarBEF – (p) Marine Biodiversity and Ecosystem Functioning
• MARC
  • (a) MAchine Readable Cataloging (often also defined as MAchine Readable Code)
  • Mailing list ARChive
  • Massachusetts Animal Rights Coalition
  • Mid-America Regional Council
• MARCENT – (p) United States Marine Forces Central Command
• MARFORCC – (p) Marine Force Component Commander
• MARRS – (a) Martyn Young, Alex Ayuli, Rudy Tambala, Russell Smith, and Steve Young (British electronic music act)
• MAS – (i) NATO Military Agency for Standardization
• MASAS – (a) Monte Agliale Supernovae and Asteroid Survey
• Maser – (a) Microwave Amplification by Stimulated Emission of Radiation
• MASH – (a) Mobile Army Surgical Hospital
• MASINT – (p) Measurement And Signature Intelligence
• MATREX – (p) Modeling Architecture for Technology, Research & EXperimentation
• MATS – (a) U.S. Military Air Transport Service (1948–1966)
• MAVS – (a/i) Mobile Artillery Vehicle System
• MAW – (s) Malawi (IOC trigram, but not FIFA or ISO 3166)
• MAX – (i) Meta-reasoning Architecture for "X"

MB

• MB – (s) Manitoba (postal symbol) – Martinique (FIPS 10-4 territory code) - Medal of Bravery (Canada)
• MBA – (i) Main Battle Area – Main Belt Asteroid – Masters of Business Administration
• MBI – (i) Moody Bible Institute
• MBBL – (i) (U.S. Armor Center) Mounted Battlespace Battle Laboratory
• MBCC – (i) Migratory Bird Conservation Commission (U.S.)
• MBCS – (i) Multi-Byte Character Set
• MBE – (p) Member of the Order of the British Empire – (i) Multistate Bar Examination (U.S.)
• MBIDST – (i) Member of the British Institute of Dental and Surgical Technologists
• MBM – (i) Meat and Bone Meal
• mbsf – metres below sea floor, a depth convention used in paleontology and oceanography
• MBT – (i) Main Battle Tank
• MBTA – (i) Massachusetts Bay Transportation Authority – Migratory Bird Treaty Act (U.S.)
• MBTI – (i) Myers-Briggs Type Indicator

MC

• mC – (s) Millicoulomb
• MC
  • (s) Macau (FIPS 10-4 territory code)
  • (i) Master of Ceremonies
  • (s) Megacoulomb
  • (i) Military Cross (bravery award)
  • (s) Monaco (ISO 3166 digram)
  • (i) Mortar Carrier
  • (s) Eleven Hundred (in Roman numerals)
• MCA
  • (i) Master of Computer Applications
  • Micro Channel Architecture
  • MultiChannel Analyzer
  • Music Corporation of America, the original name of the now-defunct MCA Inc.
• MCC
  • (i) Marylebone Cricket Club
  • Mission Control Center
  • Motor Control Center
  • Movement Control Centre
• MCD
  • (i) Minimal Cerebral Dysfunction
  • Minor civil division (U.S. Census term)
• MCDL – (i) Model Composition Definition Language
• MCFT – (i) Modified Compression Field Theory
• MCG – (i) Melbourne Cricket Ground
• MC&G – (i) Mapping, Charting, and Geodesy
• MCI – (i) Microwave Communications, Inc.
• MCIS – (i) Mellon Collie and the Infinite Sadness
• MCM – (i) Mine Counter-Measures
• MCMV – (i) Mine Counter-Measure Vessel
• MCNC
  • (i) Microelectronics Center of North Carolina
  • (i) Mixing Condensation Nucleus Counter
• MCO
  • (i) Major Combat Operation
  • (s) Monaco (ISO 3166 trigram)
  • (i) Movement Control Officer
• MCP
  • (i) Maintenance Collection Point
  • Male Chauvinist Pig
• MCR – (i) My Chemical Romance
• MCSF – (i) Marine Corps Security Forces
• MCT – (i) Movement Control Team
• MCTIS – (i) Mounted Co-operative Target Identification System
• MCU
  • (i) Marine Corps University
  • Marvel Cinematic Universe
  • Medium close-up (camera direction in British TV scripts)
  • (p) Microcontroller unit
  • (i) Milk clotting units
  • Ming Chuan University
  • Minimum coded unit (digital imaging)
  • Multipoint control unit
  • Municipal Credit Union (New York)

MD

• Md – (s) Mendelevium
• MD
  • (s) Fifteen Hundred (in Roman numerals)
  • Maryland (postal symbol)
  • (i) Medicinae Doctor (Doctor of Medicine/Medical Doctor)
  • Mentioned in Dispatches (military)
  • (s) Moldova (FIPS 10-4 country code; ISO 3166 digram)
• MDA
  • (i) Main Defensive Action/Area
  • (s) Moldova (ISO 3166 trigram) – Muscular Dystrophy Association
• MDF
  • (i) Main distribution frame
  • Medium-density fiberboard
• MDG
  • (s) Madagascar (ISO 3166 trigram)
  • (i) UN Millennium Development Goal
• MDL – (s) Moldovan leu (ISO 4217 currency code)
• MDM
  • (i) Michigan Dartmouth MIT telescope consortium
  • Master data management
• MDMA – (i) MethyleneDioxy-MethylAmphetamine (also known as "Ecstasy")
• MDNA – (p) Madonna's 12th studio album title (2012)
• MDO – (i) Membership Driven Organisation
• MDP – (i) Markov Decision Process
• MDT – (i) Mountain Daylight Time (UTC-6 hours)
• MDV – (s) Maldives (ISO 3166 trigram)
• MDW
  • (s) Chicago Midway International Airport in Chicago (IATA airport code)
  • (i) Military District of Washington
  • (s) Minnesota, Dakota and Western Railway (AAR reporting mark)

ME

• Me – (s) Messerschmitt
• ME – (s) Maine (postal symbol) – (i) Mechanical engineer[ing] – Medical examiner – Middle East – (s) Middle East Airlines (IATA code) – (i) Memory Effect – Myalgic Encephalomyelitis
• MEA – (i) Maine Educational Assessment – Middle East Airlines – Millennium Ecosystem Assessment – Minimum en route altitude – Mono-ethanol Amine – Multilateral Environmental Agreement
• MEAC – (a) Mid-Eastern Athletic Conference (ME-ac)
• MEC
  • (s) Maine Central Railroad
  • Manta, Ecuador (IATA location identifier)
  • (i) Model European Council
  • Mountain East Conference
  • Mountain Equipment Co-op
• MECC – (a) Minnesota Educational Computing Consortium (later Corporation, dissolved 1999)
• MECCA – (a) Milwaukee Exposition Convention Center and Arena, a former name for the sports venue now known as UW–Milwaukee Panther Arena
• MECO – (a) Main engine cutoff (NASA code for point in Space Shuttle assent when three main engines are shut down prior to External Tank (ET) separation)
• MEDEVAC – (p) Medical evacuation
• MEDLI - (a) Mars Science Laboratory Entry, Descent, and Landing Instrumentation - (a) Medical & Scientific Libraries of Long Island - (a) Model for Effluent Disposal using Land Irrigation
• MEDS – (a) Mission Essential Data Set
• MEF – (i) U.S. Marine Expeditionary Force – Minimum essential facility – Mission essential force
• MEG – (i) MagnetoEncephaloGraphy
• MEI – (i) Matsushita Electric Industrial Co., Ltd.
• MEK – (i) Magyar Elektronikus Konyvtar – Message encryption key – Methyl ethyl ketone – (p) Mujahideen al-Khalq
• MEL – (i) Maya Embedded Language – Michigan Electronic Library
• MELT – (a) Metallic Line/Loop Test (ing)
• MEM – (i) Message Exchange Mechanism – (p) Microelectromechanical
• MEMS – (p) Microelectromechanical System
• MEO – (a) Medium earth orbit – Most efficient organization
• MEP – (i) Mechanical Electrical Plumbing – Member of the European Parliament – Missions étrangères de Paris (French for "Paris Foreign Missions") – Model European Parliament
• MER – (i) Mars Exploration Rover
• MERL – (i) Mitsubishi Electric Research Laboratories
• MES – (i) Marconi Electronic Systems – Medium Edison screw
• MESSENGER – (p) MErcury Surface, Space ENvironment, GEochemistry and Ranging
• MET – (p) Meteorological – (a) Middle European Time
• METAR – (p) [Meteorological] Aviation Routine weather report
• METL – (i/a) Mission Essential Task List ("mettle")
• METOC – (p) Meteorological and Oceanographic
• METT-T – (a/i) Mission, Enemy, Terrain, Troops, and Time available (mnemonic)
• METT-TC – (a/i) Mission, Enemy, Terrain [and weather], Troops [and support], Time [available] and Civilian considerations (mnemonic)
• MEU – (i) U.S. Marine Expeditionary Unit – Maximum Expected Utility
• MeV – (s) Megaelectronvolt
• MEV – (i) Medical Evacuation Vehicle – Musica Elettronica Viva
• MEX – (s) Mexico (ISO 3166 trigram)
• MEZ – (i) Missile Engagement Zone
• MES – (a) Manufacturing Execution Systems

MF

• mF – (s) Millifarad
• MF – (s) Mayotte (FIPS 10-4 territory code) – Megafarad
• MFSB – (i) Mother, Father, Sister, Brother (1970s Philadelphia studio musicians collective)

MG

• mg – (s) Malagasy language (ISO 639-1 code) – Milligram
• Mg – (s) Magnesium – Megagram
• MG – (i) Machine Gun – (s) Madagascar (ISO 3166 digram) – (s) Major General – (s) Mongolia (FIPS 10-4 country code) – (i) Morris Garage
• MGA – (s) Malagasy ariary (ISO 4217 currency code)
• MGB – (i) Medium Girder Bridge, Motor Gun Boat
• MGM – (i) Metro Goldwyn Mayer – (s) Montgomery, Alabama (Airport Code)
• MGPAM – My Gym Partner's a Monkey
• MGS – (i) Mobile Gun System

MH

• mh – (s) Marshallese language (ISO 639-1 code)
• mH – (s) Millihenry
• MH – (s) Marshall Islands (postal symbol; ISO 3166 digram) – Megahenry – Montserrat (FIPS 10-4 territory code)
• MHC – (i) Major Histocompatibility Complex
• MHHW – (i) Mean Higher High Water (nautical charts)
• MHL – (s) Marshall Islands (ISO 3166 trigram)
• MHLW – (i) Mean Higher Low Water (nautical charts)
• MHRA – (i) (UK) Medicines and Healthcare products Regulatory Agency
• MHW – (i) Mean High Water (nautical charts)
• MHWN – (i) Mean High Water Neaps (nautical charts)
• MHWS – (i) Mean High Water Springs (nautical charts)
• MHz – (s) Megahertz

MI

• mi – (s) Māori language (ISO 639-1 code)
• Mi – (s) Mebi
• MI
  • (s) Malawi (FIPS 10-4 country code)
  • Michigan (postal symbol)
  • Midway Islands (ISO 3166 digram; obsolete 1986)
  • (i) Military Intelligence
• MIA – (i) Missing In Action
• MIAA
  • (i) Maryland Interscholastic Athletic Association
  • Massachusetts Interscholastic Athletic Association
  • Michigan Intercollegiate Athletic Association
  • Mid-America Intercollegiate Athletics Association
• MIB
  • (i) Men In Black
  • Mint In Box (Internet auction/trading listings)
• MIC – (a) Military Industrial Complex
• MICLIC – (p) Mine Clearing Line Charge
• MICOM – (p) Missile Command
• MICV – (i) Mechanised Infantry Combat Vehicle
• MID – (s) Midway Islands (ISO 3166 trigram; obsolete 1986)
• MIDI – (a) Musical Instrument Digital Interface
• MIDAS – (a) Man-machine Integration Design and Analysis System
• MIDS – (i) Multi-Function Information Distribution System
• MIFC – (a) Military Industrial Financial Complex
• MIFG – (s) Shallow Fog (METAR Code)
• MIFPC – (a) Military Industrial Financial Pharmaceutical Complex
• MIKE – (a) Monitoring of Illegal Killing of Elephants
• MIL – (i) Man-In-the-Loop
• MIL-AASPEM – (i) Man-In-the-Loop AASPEM
• MILAN – (p) Missile d´infanterie léger antichar (French, "Anti-Tank Light Infantry Missile")
• MILC – (a) Mirrorless interchangeable-lens camera
• MILES – (a) Multiple Integrated Laser Engagement System (live combat simulation)
• MILF
  • (i) Moro Islamic Liberation Front
  • (a) Mother I'd Like to Fuck
• MILSATCOM – (p) Military Satellite Communications
• MILSET – (a) Mouvement International pour le Loisir Scientifique Et Technique (French, "International Movement for Leisure Activities in Science and Technology")
• MILSTRIP – (p) Military Standard Requisitioning and Issue Procedure DLMSO MILSTRIP Manual
• MIMAROPA – (p) Mindoro, Marinduque, Romblon, Palawan (a region in the Philippines)
• MIMOSA – (a) MIcroMeasurements Of Satellite Acceleration
• MIMPT – (i) Member of the Institute of Maxillofacial Prosthetists and Technologists
• MIP
  • (a) Multilateral Interoperability Programme
  • Multiple Identity Poster
• MIPC – (a) Military Industrial Pharmaceutical Complex
• MIRA – (a) MILAN Infra-Red Acquisition (thermal sight)
• MIRV – (a) Multiple Independent Reentry Vehicle
• MIS
  • (a) Management Information Systems
  • Museum Information System
• MISREP – (p) Mission Report
• MISSI – (a) Multilevel Information System Security Initiative
• MIT
  • (i) Massachusetts Institute of Technology
  • methylisothiazoline
  • Milli Istihbarad Teskilati (Intelligence service of Turkey)
• MITL – (i) Man-In-The-Loop
• MITS – see entry

MJ

• mJ – (s) Millijoule
• MJ
  • (s) Megajoule
  • (i) Michael Jordan
• MJD – (i) Modified Julian Day
• MJP – (i) Military Judgement Panel

MK

• mk – (s) Macedonian language (ISO 639-1 code)
• mK – (s) Millikelvin
• MK
  • (s) Air Mauritius (IATA code)
  • Macedonia (ISO 3166 digram; FIPS 10-4 country code)
  • (i) Mandalskameratene (Norwegian football club)
  • (s) Megakelvin
  • (i) Milton Keynes
  • Missionary Kids
  • Mortal Kombat (1992 video game)
  • Mortal Kombat (2011 video game)
• mkd – (s) Macedonian language (ISO 639-2 code)
• MKD
  • (s) Macedonian denar (ISO 4217 currency code)
  • Republic of Macedonia (ISO 3166 trigram)
• MKG – (i) Michael Kidd-Gilchrist (American basketball player)
• MKO – (i) Mojahedin-e-Khalq Organization (Persian, "People's Mujahedin of Iran")
• MKS
  • (i) Metre–Kilogram–Second (system of units)
  • (p) MKS Inc. software company
• MKSA – (i) Metre–Kilogram–Second–Ampere (system of units)
• MKT
  • (i) Missouri-Kansas-Texas Railroad (1865–1989)
  • Mortal Kombat Trilogy

ML

• ml – (s) Malayalam language (ISO 639-1 code)
• mL – (s) Millilitre
• ML
  • (s) Mali (FIPS 10-4 country code; ISO 3166 digram)
  • (i) Maximum Likelihood
  • (s) Megalitre
• MLA
  • (i) Martial Law Administration of Bangladesh
  • Master of Landscape Architecture
  • Medical Library Association
  • Member of Legislative Assembly
  • Modern Language Association
  • Mutual legal assistance treaty
  • Myelosis Leucemica Acuta
• MLB – (i) Major League Baseball
• MLC – (i) Member of the Legislative Council (in India)
• MLE – (i) Maximum likelihood estimation
• mlg – (s) Malagasy language (ISO 639-2 code)
• MLHW – (i) Mean Lower High Water (nautical charts)
• MLI – (s) Mali (ISO 3166 trigram)
• MLK – (i) Martin Luther King, Jr.
• MLL – (i) Major League Lacrosse
• MLLW – (i) Mean Lower Low Water (nautical charts)
• MLP – My Little Pony
• MLRS – (i) Multiple-Launch Rocket System
• MLS
  • (i) Major League Soccer
  • Multiple Listing Service
  • Multilevel security
• MLSE
  • (i) Maple Leaf Sports & Entertainment (owner of several Toronto-based sports teams)
  • Maximum likelihood sequence estimation
• MLSR – (i) Missing, Lost or Stolen Report
• mlt – (s) Maltese language (ISO 639-2 code)
• MLT – (s) Malta (ISO 3166 trigram)
• MLVW – (i) Medium Logistics Vehicle, Wheeled
• MLW – (i) Mean Low Water (nautical charts)
• MLWN – (i) Mean Low Water Neaps (nautical charts)
• MLWS – (i) Mean Low Water Springs (nautical charts)

MM

• mm – (s) Millimetre
• Mm – (s) Megametre
• MM – (i) Military Medal – (s) Myanmar (ISO 3166 digram) – Two Thousand (in Roman numerals)
• MMA – (i) Mixed martial arts – Moving Mechanical Assembly
• MMC – (p) Machinist's Mate, Chief (USN rating) – (i) Materiel Management Centre
• MMCM – (p) Machinist's Mate, Master Chief (USN rating) – (i) Magnetic Mine Counter Measure
• MMCS – (p) Machinist's Mate, Senior Chief (USN rating)
• MMEV – (i) Multi-Mission Effects Vehicle
• MMI – (i) Man-Machine Interface
• MMI – (i) McLean Meditation Institute
• MMIC – (i) Mindfulness & Meditation Instructor, Certified
• MMIC – (i) McLean Meditation Institute Certified
• MMI – (i) Magical MonkeyZ Inc.
• MMK – (s) Burmese kyat (ISO 4217 currency code)
• MMO – (i) Massively Multiplayer Online (computer game)
• MMOR – (i) Master of Management in Operations Research
• MMORPG – (i) Massively multiplayer online role-playing game
• MMPR – Mighty Morphin Power Rangers
• MMR – (i) Measles, Mumps and Rubella vaccine – (s) Myanmar (ISO 3166 trigram)
• MMS – (i) Multimission Modular Spacecraft
• MMU – (i) Manchester Metropolitan University – (i) Manned Manoeuvring Unit
• MMW – (p) Millimetre Wave (radar, from "mm Wave")

MN

• mn – (s) Mongolian language (ISO 639-1 code)
• mN – (s) Millinewton
• Mn – (s) Manganese
• MN – (s) Meganewton – Minnesota (postal symbol) – Monaco (FIPS 10-4 country code) – Mongolia (ISO 3166 digram)
• MNB – (p) Multinational Brigade
• MNB C – (p) Multinational Brigade Centre (KFOR)
• MND – (i) Motor Neurone Disease – (p) Multinational Division
• MNE – (s) Montenegro (ISO 3166 trigram)
• MNG – (i) Multiple-image Network Graphics – (s) Mongolia (ISO 3166 trigram)
• MNMF – (i) Multi-National Maritime Force
• MNP – (s) Northern Mariana Islands (ISO 3166 trigram)
• MNS – (i) Mission Needs Statement
• MNT – (p) Molecular nanotechnology – (s) Mongolian tugrik (ISO 4217 currency code)

MO

• mo – (s) Moldovan language (ISO 639-1 code)
• Mo – (s) Molybdenum
• MO – (s) Macau (ISO 3166 digram) – (i) Medical Officer – (s) Missouri (postal symbol) – (i) modus operandi (Latin, "mode of operation") – (s) Morocco (FIPS 10-4 country code) [mutual oral]
• MOA – Museum of Art (Brigham Young University)
• MOAB – (a) Massive Ordnance Air Blast (official) – Mother Of All Bombs (slang)
• MOB – (i) Man Over Board – Marching Owl Band – Movable Object Block
• MOC – (i) Macedonian Orthodox Church – Measure Of Capability – Mission Operations Centre – My Own Creation (Lego)
• MOCAS – (a) Mechanization Of Contract Administration Services
• MoD – (i) Ministry of Defence (United Kingdom) and various other countries
• MOD – (i) Magneto-optical disc – Masters of Deception – Minimum Object Distance – Multiple Organ Dysfunction
• MoDAF – (p) Ministry of Defence Architecture Framework ("moh-daff")
• modem – (p) Modulator-Demodulator
• ModSAF – (p) Modular Semi-Automated Forces (military simulation)
• Moe – (a) Marvel of entertainment
• MOE – (i) Measure Of Effectiveness
• MOF – (a/i) Ministry of Finance (Japan)
• MOFA – (a/i) Ministry of Foreign Affairs (Japan)
• MOH – (a/i) Medal of Honor – Music On Hold
• MOID – (i) Minimum Orbital Intersection Distance
• MOJWA – (i) Movement for Oneness and Jihad in West Africa
• mol – (s) Moldovan language (ISO 639-2 code) – mole (unit)
• MOLO – (a) Mobile Other Licensed Operator (UK)
• MoM – (a) Multiple of the median
• MOM – (a) Message Oriented Middleware
• MOM – (a) Master's Degree in Oriental medicine
• MoMA – (a) Museum of Modern Art (NYC)
• mon – (s) Mongolian language (ISO 639-2 code)
• MOND – (p) Modified Newtonian Dynamics
• MOO – (i) Measure Of Outcome
• MOOTW – (p) Military Operations Other Than War ("moot-double-you")
• MOP – (s) Macau pataca (ISO 4217 currency code) – (i) Measure Of Performance
• MOPE – (a) Ministry of Population and Environment (Nepal) – Most Oppressed People Ever (politics)
• MOPP – (i/a) Mission-Oriented Protective Posture
• MORP – (a) Meteorite Observation and Recovery Project
• MORS – (i) Military Operations Research Society
• MOS – (i) Military Occupational Specialty – (a) Mit Out Sound / Motor Only Sync – (i) Mobile Object System – Model Output Statistics – Multiplayer Online Services - (a) Mean Opinion Score
• MOS-CQ - (a) Mean Opinion Score - Conversational Quality (ITU-T P.800.1)
• MOS-LQ - (a) Mean Opinion Score - Listening Quality (ITU-T P.800.1)
• MOSFET – (a) Metal-Oxide-Semiconductor Field-Effect Transistor
• MOSS – (p) MObile Submarine Simulator – (a) Moving Object Support System
• MOT – (i) Ministry of Transport (UK)
• MOTA – (i) Member of the Orthodontic Technicians Association
• MOTESS – (a) Moving Object and Transient Event Search System
• MOTO – (a) Mail Order / Telephone Order – Master of the obvious
• MOU – (i) Memorandum Of Understanding
• MOUT – (i) Military Operations in Urban[ized] Terrain
• MOVES – (a) Modeling, Virtual Environments, and Simulation Institute
• MOW – (i) Maintenance of way (also MW)
• MOZ – (s) Mozambique (ISO 3166 trigram)

MP

• MP – (i) Magic points – (s) Mauritius (FIPS 10-4 country code) – (i) Member of Parliament – Military Police – Missouri Pacific – (s) Northern Mariana Islands (postal symbol; ISO 3166 digram)
• mPa – (s) Millipascal
• MPa – (s) Megapascal
• MPA – (i) Maritime Patrol Aircraft – Master of Public Administration
• MPAA – (i) Motion Picture Association of America
• MPC – (i) Minor Planet Center – Minor Planet Circular
• MPC – (i) Military Payment Certificate
• MPEC – (i) Minor Planet Electronic Circular
• MPEG – (a) Motion Pictures (Coding) Experts Group
• MPEV – (i) Multi-Purpose Engineering Vehicle
• MPF – (i) Maritime Prepositioning Force
• MPFC – (i) Medial PreFrontal Cortex
• MPG - (i) Miles Per Gallon
• MPMC – (i) Medial PreMotor Cortex
• MPSI – (i) Member of the Pharmaceutical Society of Ireland
• MPSoC – (i) MultiProcessor System-on-Chip
• MPSRON – (p) Maritime Propositioning Ship Squadron

MQ

• MQ – (s) Martinique (ISO 3166 digram) – Midway Islands (FIPS 10-4 territory code)

MR

• mr – (s) Marathi language (ISO 639-1 code)
• MR – (s) Mauritania (FIPS 10-4 country code; ISO 3166 digram)
• MR-ATGW – (i) Medium-Range Anti-Tank Guided Weapon
• MRAV – (i) Multi-Role Armoured Vehicle
• MRBM – (i) Medium Range Ballistic Missile
• MRC – (i) Maintenance Requirements Card
• MRD – (i) Motorized Rifle Division
• MRE – (i) Meal Ready to Eat (U.S. military rations)
• MRGO – (i) Mississippi River–Gulf Outlet Canal (also referred to as MR-GO or "Mr. Go")
• MRGW – (i) Medium-Range Guided Weapon
• mri – (s) Māori language (ISO 639-2 code)
• MRI – (i) Magnetic Resonance Imaging
• MRL – (i) Multiple Rocket Launcher
• MRO
  • (i) Maintenance, Repair and Operating
  • Mars Reconnaissance Orbiter
  • (s) Mauritanian ouguiya (ISO 4217 currency code)
• MRPharmS – (i) Member of the Royal Pharmaceutical Society (Great Britain)
• MRR
  • (i) Maximum Rock and Roll
  • Minimum-Risk Route
  • My Restaurant Rules
• MRS – (i) Magnetic Resonance Spectroscopy
• MRSA – (i) Methicillin-resistant Staphylococcus aureus
• MRT
  • (i) Mass Rapid Transit — used as either an official or unofficial name for metro systems in Singapore, Kaoshiung, Bangkok, Taipei, Chennai, and Delhi
  • (s) Mauritania (ISO 3166 trigram)
• MRTFB – (i) U.S. Major Range and Test Facility Base

MS

• ms
  • (s) Malay language (ISO 639-1 code)
  • Millisecond
• mS – (s) Millisiemens
• Ms – (s) Megasecond
• MS
  • (i) mano sinistra (Latin, "left hand")
  • (p) manuscript
  • (i) Master of Science
  • (s) Megasiemens
  • (p) Microsoft (sometimes M$)
  • (s) Mississippi (postal symbol)
  • Montserrat (ISO 3166 digram)
  • (i) Multiple Sclerosis
• M&S
  • (i) Modelling & Simulation
  • Marks & Spencer
• msa – (s) Malay language (ISO 639-2 code)
• MSB
  • (i) Main Support Battalion
  • Most Significant Bit (or Byte)
• MSD – (i) Minimum Safe Distance
• MSDB – (i) Multi Source Data Base
• MSDE
  • (i) Maryland State Department of Education
  • (p) Microsoft Data[base] Engine
  • Microsoft SQL Server 2000 Desktop Engine
  • (i) Military Scenario Development Environment
  • Mission Simulation Dynamic Engine
• MSDL – (i) Military Scenario Definition Language
• MSE – (i) Multiple Subscriber Element
• MSEC – (p) Message Security Encryption Code ("emm-sec")
• MSG
  • (i) MonoSodium Glutamate
  • Madison Square Garden (either the 1879, 1890, 1925, or current versions of the venue)
• MSH
  • (i) Medium Support Helicopter
  • Mount Saint Helens
• MSI
  • (i) Micro-Star International
  • (p) Multispectral imagery
• MSIE
  • (i) Microsoft Internet Explorer
  • Master of Science in Industrial Engineering
• MSL
  • (i) Mars Science Laboratory
  • Mean Sea Level
  • (p) Missile
• MSLP – (i) Mean Sea Level Pressure
• MSM
  • (p) Mainstream media
  • (i) Men who have sex with men
  • Mount St Mary's School
• MSN
  • (i) Microsoft Network
  • Master of Science in Nursing
• MSNBC – (i) Microsoft National Broadcasting Company Cable news channel (see also msnbc.com)
• MSO – (i) Multiple System Operator
• MSPA
  • (p) Migrant and Seasonal worker Protection Act
  • (a) MS Paint Adventures
• MSPB – (i) Merit Systems Protection Board
• MSR
  • (i) Main Supply Route
  • Module Service Record
  • (s) Montserrat (ISO 3166 trigram)
  • (i) Motor Schlepp Regulung
  • Mountain Safety Research (outdoor supplies manufacturer)
• MSSA – (i) Methicillin-susceptible Staphylococcus aureus
• MST
  • (i) Madison Symmetric Torus
  • Mountain Standard Time (UTC-7 hours)
• MST3K or MST3k – (i) Mystery Science Theater 3000
• MSU
  • (i) Michigan State University
  • Montana State University
  • Mountain State University
  • Lomonosov Moscow State University (Russia, a.k.a. MGU)

MT

• mt – (s) Maltese language (ISO 639-1 code)
• mT – (s) Millitesla
• Mt – (s) Meitnerium
• MT
  • (s) Malta (FIPS 10-4 country code; ISO 3166 digram)
  • Megatesla
  • Montana (postal symbol)
  • (i) Motor Transport (military)
• MTA
  • (i) Metropolitan Transportation Authority (Boston) (now Massachusetts Bay Transportation Authority)
  • Metropolitan Transportation Authority (New York)
• MTBF – (i) Mean time between failures
• MtF – (i) Male-to-female transsexual
• MTF
  • (i) Magnetized target fusion
  • Medical Treatment Facility
  • Message Text Format
  • Modulation transfer function (optics)
• MTG – (i) Magic: The Gathering
• MTL
  • (s) Maltese lira (ISO 4217 currency code)
  • (i) Mean Tide Level (nautical charts)* MTM – (i) Methods-Time Measurement
• MTOE – (p) Modified Table of Organization and Equipment ("emm-toe")
• MTP
  • (i) Maritime Tactical Publication
  • Materiel Transfer Plan
  • Mission Training Plan
• MTQ – (s) Martinique (ISO 3166 trigram)
• MTR
  • (i) Main and Tail Rotor (helicopter type)
  • Mass Transit Railway (Hong Kong metro system)
  • Military-Technological Revolution
• MTS
  • (i) Maintenance Training System
  • Manitoba Telecom Services
  • Michigan Terminal/Timesharing System
  • Movement Tracking System
  • Multichannel television sound
  • Multi-Technical Services
• MTT – (p) Methylthiazol tetrazolium (assay)
• MTU – (i) Tankovei Mostoukladchik (Russian Танковый Мостоукладчик, "Tank Bridge-Layer") †
• MTV
  • (i) MainosTeleVisio (Finnish commercial TV company)
  • Music TeleVision
• MTVL – (i) Mobile Tracked Vehicle, Light
• MTWS – (i) MAGTF Tactical Warfare System

MU

• MU – (s) Mauritius (ISO 3166 digram) – Oman (FIPS 10-4 country code; from Muscat)
• MUA – (i) Meritorious Unit Award – Military Utility Assessment
• MUR – (s) Mauritius rupee (ISO 4217 currency code)
• MUS – (s) Mauritius (ISO 3166 trigram)

MV

• mV – (s) Millivolt
• MV – (s) Maldives (FIPS 10-4 country code; ISO 3166 digram) – Megavolt – (i) Motor Vehicle – Motor Vessel
• MVC – (i) Missouri Valley Conference
• MVFC – (i) Missouri Valley Football Conference
• MVNO – (i) Mobile virtual network operator
• MVR – (s) Maldivian rufiyaa (ISO 4217 currency code)

MW

• mW – (s) Milliwatt
• MW
  • (i) Maintenance of way (also MOW)
  • (s) Malawi (ISO 3166 digram)
  • (i) Medium Wave (radio)
  • (s) Megawatt
  • (i) Mountain West (Conference) (formal initialism since July 2011)
• MWC
  • (i) Maritime Warfare Centre (various nations)
  • Mountain West Conference (still used informally, although the league has adopted "MW")
• MWESH – (p) Machismo Wizards Extended SHelter (operating system)
• MWI – (s) Malawi (ISO 3166 trigram)
• MWK – (s) Malawian kwacha (ISO 4217 currency code)
• MWOA – (i) Mount Wilson Observatory Association
• MWR – (i) Morale, Welfare, and Recreation
• MWTB - (a) Mounted Warfare Test Bed

MX

• MX – (a) Mail Exchange – (s) Mexico (FIPS 10-4 country code; ISO 3166 digram) – (p) Missile eXperimental
• MXN – (s) Mexican peso (ISO 4217 currency code)

MY

• my – (s) Burmese language (ISO 639-1 code)
• MY – (s) Malaysia (FIPS 10-4 country code; ISO 3166 digram)
• mya – (s) Burmese language (ISO 639-2 code) – (i) million years ago
• MYOB – (i) Mind Your Own Business
• MYR – (s) Malaysian ringgit (ISO 4217 currency code)
• MYS – (s) Malaysia (ISO 3166 trigram)
• MYT – (s) Mayotte (ISO 3166 trigram)

MZ

• MZ – (i) Mach-Zehnder (interferometer) – (s) Magnetic Azimuth – (i) Move, Zig (Zero Wing) – (s) Mozambique (FIPS 10-4 country code; ISO 3166 digram)
• MZN – (s) Mozambique metical (ISO 4217 currency code)