| Abbreviation | Definition |
|---|---|
| M2U | Music to You |
| MAASON | Marketing Affordable Analysis Standard Organizing Network |
| MAGC | Make A Green Choice |
| MAGIC | Many Anti Gross Iron Cats |
| MALP | Massive Academic Learning Portal |
| MAO | Multi Anime Opening |
| MAPB | Mothers Against Police Brutality |
| MBBF | My Brother's Best Friend |
| MBBS | Married But Beautiful Sight |
| MBTB | Murder By The Book |
| MBW | Merriadoc Brandybucks Website |
| MeFi | MetaFilter |
| MFHM | Mega Fantasy Heroine Maker |
| MGNR | Monster Goose Nursery Rhymes |
| MHBHJ | Marks Head Bobbers and Hand Jobbers |
| MHC | Mile High Club |
| MHH | MovieHaHd |
| MI2 | Modular Instruments, Inc. |
| MIA | Marxists Internet Archive |
| MIGM | May Is Gold Month |