| FF | degree of fineness of abrasive particles; fat-free; father factor; fecal frequency; fertility factor... |
|---|---|
| SI | International System of Units [Fr. le Systeme International d'Unites]; sacroiliac; saline infusion; ... |
| FNA | Fine Needle Aspiration |
| FNAB | Fine Needle Aspiration Biopsy |
| EXAFS | extended x-ray absorption fine structure |