| f-NE | free norepinephrine |
|---|---|
| f-NM | free normetanephrine |
| F-SP | special form [Lat. forma specialis] |
| F/A | fetus active |
| f/cc | fibers per cubic centimeter of air |
| F/S | female, spayed [animal]; frozen section |
| F/U | Follow Up |
| F/U | follow-up, fundus of umbilicus |
| F0, | F1 coupling factor |
| F1, | F2 etc. first, second, etc., filial generation |