| FF | degree of fineness of abrasive particles; fat-free; father factor; fecal frequency; fertility factor... |
|---|---|
| BSU | Bartholin, Skene, urethral [glands]; basic structural unit; British standard unit |
| LISREL | linear structural relation |
| SFIS | structural family interaction scale |
| SRU | sample ratio units; side rails up; solitary rectal ulcer; structural repeating unit |