| Abbreveation | | description |
| M8 | | Mate |
| MSG | | Message |
| MTE | | My Thoughts Exactly |
| MMFU | | my mate fancies you |
| MTFBWU | | may the force be with you |
| MYOB | | Mind your own Business |
| mo | | Moment |
| MMS | | Multimedia Messaging System |
| M8 or M8 | | Mate or Mates |
| MFD | | Multi-Function Device |
| MfG | | Mit freundlichen Gruessen |
| MHBFY | | My Heart Bleeds For You |
| MIHAP | | May I Have Your Attention Please |
| MKOP | | My Kind Of Place |
| MM | | Market Maker |
| MMHA2U | | My Most Humble Apologies To You |
| MOMPL | | One Moment Please |
| MOO | | Mud, Object-Oriented |
| MOOS | | Member Of The Opposite Sex |
| MorF | | Male or Female? |
| MOSS | | Member Of The Same Sex |
| MOTAS | | Member Of The Appropriate Sex |
| MOTD | | Message Of The Day |
| MOTSS | | Members Of The Same Sex |
| MTBF | | Mean Time Between Failure |
| MTFBWY | | May The Force Be With You |
| MUBAR | | Messed up Beyond All Recognition |
| MWBRL | | More Will Be Revealed Later |
| mofo | | Mother Fucker |
