| F/U | Follow Up 
| Others |
| F/U | Follow-Up
| Others |
| FU | F***ed Up
| Others |
| FU | Fairfield University
| Others |
| FU | Family Unit
| Others |
| FU | Family Urban
| Others |
| FU | Farmacopea Ufficiale
| Others |
| FU | Farmacopeia Ufficiale
| Others |
| FU | Fart Underwater (submarine sound)
| Others |
| FU | Fearless Unit
| Others |
| FU | Feedback Unit
| Others |
| FU | Felix Unger
| Others |
| FU | Fertilizer Use
| Others |
| FU | Fibrinolytic Units
| Others |
| FU | Field Unit
| Others |
| FU | Fighter Underground
| Others |
| FU | File to URL
| Others |
| FU | File Upload
| Others |
| FU | File Uploader
| Others |
| FU | Finishing Unit
| Others |
| FU | Finite Union
| Others |
| FU | Finitions Updated
| Others |
| FU | Fire Unit
| Others |
| FU | First User
| Others |
| FU | Fixture Unit
| Others |
| FU | Flight Unit
| Others |
| FU | Florida University
| Others |
| FU | Flows Unlimited
| Others |
| FU | Fluffy Unicorn
| Others |
| FU | Fluorescence Unit
| Others |
| FU | Food Unit
| Others |
| FU | Football United
| Others |
| FU | For Us
| Others |
| FU | For Utm
| Others |
| FU | Forces Unknown
| Others |
| FU | Forcible Union
| Others |
| FU | Fordham University
| Others |
| FU | Forecast Unit
| Others |
| FU | Forever Unchained
| Others |
| FU | Forever Unloved
| Others |
| FU | Formerly Undesirable
| Others |
| FU | Formula Unit
| Others |
| FU | Fortran Unit
| Others |
| FU | Forward Units
| Others |
| FU | Forward User
| Others |
| FU | Foul Up
| Others |
| FU | Fraction Unbound
| Others |
| FU | Frag University
| Others |
| FU | Francis Urquhart
| Others |
| FU | Freaking Ugly
| Others |
| FU | Fridays Unyoked
| Others |
| FU | Friends University
| Others |
| FU | Frost Up
| Others |
| FU | Fude University
| Others |
| FU | FUel
| Others |
| FU | Functional Unit
| Others |
| FU | Fundamental Unit
| Others |
| FU | Funky Underpants
| Others |
| FU | Funny Uncle
| Others |
| FU | Furman University
| Others |
| FU | Future Unit
| Others |
| FU | Future Unity
| Others |
| FU | Future's Unpredictable
| Others |