| Acronym | Definition |
|---|
| FU | Forget You (polite form) |
| FU | Follow-Up |
| FU | Fuse |
| FU | Smoke (aviation meteorology) |
| FU | Freie Universität (Berlin, Germany) |
| FU | Fluorouracil |
| FU | Florida University |
| FU | File Upload |
| FU | Future Use |
| FU | Fordham University |
| FU | Felician University (Franciscan University of New Jersey) |
| FU | Functional Unit |
| FU | First Union (US east coast bank) |
| FU | Furman University (Greenville, SC) |
| FU | Fairfield University |
| FU | Fisk University |
| FU | Foul Up (polite form) |
| FU | Freaks United |
| FU | Follicular Unit |
| FU | Franklin University (Columbus, Ohio) |
| FU | Forretningsudvalg (Danish) |
| FU | Felix Unger (The Odd Couple) |
| FU | Fine Used (philately) |
| FU | Friends University (Kansas) |
| FU | Finlandia University |
| FU | Field Unit (US DoD) |
| FU | Fire Unit |
| FU | Fatih University (Istanbul, Turkey) |
| FU | Forever United |
| FU | Fire & Update |
| FU | Flight Unit |
| FU | Flasher Unit |
| FU | Formula Unit (chemistry) |
| FU | Fixture Unit (plumbing) |
| FU | Functional User |
| FU | Firing Unit |
| FU | Freaking Ugly (polite form) |
| FU | Forward User |
| FU | Fun University (That 70's Show) |
| FU | Forensic Unit |
| FU | Freidman Unit (political slang/meme for six months) |
| FU | Fuerza Unida (Spanish: Thread of Justice; San Antonio, TX) |
| FU | Forever Unchained |
| FU | Fiscal Unit |
| FU | Flamingoz Unlimited (website) |
| FU | Feati Universtiy |
| FU | Farmacias Unidas (Guatemala) |