| Abbreviation | Definition |
|---|---|
| FIT | Fæcal Immunochemical Test |
| FIT | Fecal Immunochemical Test |
| FK | Foreign Keys |
| FLA | Fujitsu Laboratories of America |
| FLDX | Flouresceinated Lysine-Fixable Destran |
| FLEC | Field and Laboratory Emission Cell |
| FLNR | Flerov Laboratory for Nuclear Reactions |
| FLNR | Flerov Laboratory of Nuclear Reactions |
| FLO | First Living Organism |
| FLR | Final Laboratory Report |
| FMBL | Forest Measurements and Biometrics Laboratory |
| FML | Friedrich Miescher Laboratory |
| FML | Functional Materials Laboratory |
| FMO | Flavin MonoOxygenase |
| FMRL | Fire and Materials Research Laboratory |
| FMSL | Flinders Mathematical Sciences Laboratory |
| FMSL | Forensic Medical Science Laboratory |
| FNAL | Fermi National Accelerator Laboratory |
| FNAL | Fermilab National Accelerator Laboratory |
| FND | First Noticeable Difference |