| FAC | Fast As Can | Transportation › Maritime |
| FAF | Funny As Freak | Message › Chat |
| FATF | Financial Action Task Force | Organisation › International |
| FAB | Fabulous | Message › Chat |
| FANS | Future Air Navigation System | Aerospace |
| FAD | Flavin-Adenine Dinucleotide | Biotechnology |
| FADEC | Full Authority Digital Engine Control | Aerospace |
| FAAK | Falling Asleep At Keyboard | Message › Chat |
| FAY | Freak All You | Message › Chat |
| FAS | Free Alongside Ship | Transportation › Maritime |