| Abbreviation | Definition |
|---|---|
| FUN | Families United for Novak |
| FUN | Family Unschoolers Network |
| FUN | For Unlawful Nawledge |
| FUN | For Unlawful Nowledge |
| FUN | Freaking Unbelievable Niceness |
| FUN | Funky University Nutters |
| FUN | Further Underpinning for Novices |
| FUR | Flexible Ultranifty Rfu |
| FUSS | Fifty Until Social Security |
| FUWB | Fun Unanimous Workout Board |
| FVD | Fallen Vampiric Devil |
| FWB | Friend With Benefits |
| FWBN | Friend With Big Nose |
| FWO | Fish World Order |
| FWO | Fouad World Order |
| FWWWM | Fast Women Whom Want Money |
| FWYB | Friends With Yodeling Benefits |
| FX | Farse Xtreme |
| FX | Female Xperience |
| FYI | F*** You Idiot |