| M | Module 
| Others |
| M | Molar
| Others |
| M | Molecular
| Others |
| M | Molto (Italian coin grade equivalent to Good)
| Others |
| M | Monday
| Others |
| M | Monitor
| Others |
| M | Monocytes
| Others |
| M | Months
| Others |
| M | Moronic
| Others |
| M | Motivation
| Others |
| M | Motor
| Others |
| M | Motorsport
| Others |
| M | Mozilla
| Others |
| M | Mud, Muddy
| Others |
| M | Multimedia
| Others |
| M | Multiplayer
| Others |
| M | Multiple
| Others |
| M | Multiply
| Others |
| M | Munich
| Others |
| M | Murder
| Others |
| M | Murderer
| Others |
| M | Muscle
| Others |
| M | Music
| Others |
| M | Mutual
| Others |
| M | Mystery
| Others |
| M | Nautical mile
| Others |
| M | Negative connection
| Others |
| M | Number of Revolutions Required for the Rendezvous
| Others |
| M | one thousand
| Others |
| M | The Maintenance
| Others |
| M | The Multiplicative
| Others |
| M | Thousand (Roman Numeral)
| Others |
| M | Up to 81 mph
| Others |
| M A T H S | Mentally Affected Teachers Harassing Students
| Others |
| M Glam. | Mid Glamorgan
| Others |
| M Of G | Manual of Guidance
| Others |
| M TECH | Michigan Tech
| Others |
| M$ | Micronation Dollar
| Others |
| M$ | Micronational dollar
| Others |
| M&A | Management and Analysis
| Others |
| M&A | Marketing and Advertising
| Others |
| M&A | Merger and Acquisition
| Others |
| M&A | Mergers and Acquisitions
| Others |
| M&A | Monitoring and Assessment
| Others |
| M&C | Maintenance And Checkout
| Others |
| M&C | Meet and Confer
| Others |
| M&C | Milk and Cream
| Others |
| M&C | Monitor and Control
| Others |
| M&C | Monitor and Control panel
| Others |
| M&CE | Manufacturing and Component Engineering
| Others |