| FEV | familial exudative vitreoretinopathy; forced expiratory volume |
|---|---|
| FEV1, | FEV1 forced expiratory volume in one second |
| FIV | feline immunodeficiency; forced inspiratory volume |
| FIV1 | forced inspiratory volume in one second |
| FRV | full-length retroviral [sequence]; functional residual volume |