| Abbreviation | Definition |
|---|---|
| MOC | Masters Of Chaos |
| MOC | Member Of the Conclave |
| MOC | Members Of Coruscant |
| MODOK | Mental Mechanized Organism Designed Only for Killing |
| MOM | Mean Old Monster |
| MOM | Ministers Of Mystery |
| MOM | Ministry Of Mayhem |
| MOO | Mothers Opposed to the Occult |
| MOS | Mastery Of Stealth |
| MOSF | Men Of Science Fiction |
| MOSF | Museum of Science Fiction |
| MOSH | Mostly Organic Substrate Human |
| MOSS | Mace Of the Shadowed Soul |
| MOTAS | Mystery Of Time And Space |
| Mothership | A large spacecraft from which smaller crafts depart. |
| MOTS | Mystery Of Time and Space |
| MOTU | Master Of The Universe |
| MR | Maximum Ride |
| MR | Minimal Reality |
| MSA | Mystical Shadow Angel |