| FF | degree of fineness of abrasive particles; fat-free; father factor; fecal frequency; fertility factor... |
|---|---|
| FJS | finger joint size |
| IS | ileal segment; immediate sensitivity; immune serum; immunosuppression; impingement syndrome; incenti... |
| ISI | infarct size index; initial slope index; injury severity index; Institute for Scientific Information... |
| MSM | medium-size molecule; mineral salts medium |