| Abbreviation | Definition |
|---|---|
| MROT | Most Recent On Time |
| MRW | My Reaction When |
| MS | Mighty Special |
| MS | Missing Something |
| MSA | Merciful, Selfless, And Adorable |
| MSA | Move Slow A** |
| MSD | Might Suddenly Disappear |
| MSE | Made Somewhere Else |
| MSF | Multi Streaming Facility |
| MSI | Mindless Self Indulgence |
| MSN | Media Serial Number |
| MSN | Mind Softening Nutrasweet |
| MSN | Mobile Sim Number |
| MSN | Money Stops Nonsense |
| MSN | My Screen Name |
| MSOY | Multiple Shades Of You |
| MSPG | Messaging Systems & Paging Group |
| MSPG | Messaging Systems Products Group |
| MSU | Make Stuff Up |
| MSUAWGA | Making S**t Up As We Go Along |