| AZO | [indicates presence of the group -N:N-] |
|---|---|
| XO | presence of only one sex chromosome; xanthine oxidase |
| FA | false aneurysm; Families Anonymous; Fanconi anemia; far advanced; fatty acid; febrile antigen; femor... |
| FAI | first aid instruction; free androgen index; functional aerobic impairment; functional assessment inv... |
| FRC | Federal Radiation Council; frozen red cells; functional reserve capacity; functional residual capaci... |