| FADF | fluorescent antibody dark field |
|---|---|
| FEER | field echo with even echo rephasing |
| FF | degree of fineness of abrasive particles; fat-free; father factor; fecal frequency; fertility factor... |
| FFE | fast field echo; fecal fat excretion |
| FFF | degree of fineness of abrasive particles; field-flow fractionation; flicker fusion frequency |