| Abbreviation | Definition |
|---|---|
| FNBN | For Nerds By Nerds |
| FnF | Friends and Family |
| FNYFA | Funny Face |
| FO | F*** Off |
| FO | First Off |
| FO | Friends Of |
| FOAF | Friend Of A friend |
| FOB | Fabulous Oriental Being |
| FOB | Fine Oriental Boy |
| FOB | Frequently Out of the Building |
| FOBA | Fear Of Being Alone |
| FOBL | Falling Off Bed Laughing |
| FOCL | Falling Off Chair Laughing |
| FOCLMAO | Fell Off Chair Laughin My A** Off |
| FOCLMAO | Fell Off Chair Laughin My Ass Off |
| FOCUS | Forum Of Children United to Succeed |
| FOE | Friends Of Elite |
| FOF | Friend Of a Friend |
| FOF | Friend Of Friend |
| FOG | Four Old Guys |