| FFF | degree of fineness of abrasive particles; field-flow fractionation; flicker fusion frequency |
|---|---|
| FGF | father's grandfather; fibroblast growth factor; fresh gas flow |
| FIF | feedback inhibition factor; fibroblast interferon; forced inspiratory flow; formaldehyde-induced flu... |
| FIF50 | forced inspiratory flow at 50% of forced vital capacity |
| FIFR | fasting intestinal flow rate |