| faint(noun, weak, sick, unhealthy) |
| fainting fit(noun, weak, sick, unhealthy) |
| faintness(noun, weak, sick, unhealthy) |
| falling sickness |
| familiar(adjective, close, easy, friendly, relaxed) |
| fatigue(noun, weak, sick, unhealthy) |
| feeble(noun, weak, sick, unhealthy) |
| feebleness(noun, weak, sick, unhealthy) |
| fits and starts(expression, idiom) |
| flabbiness(noun, weak, sick, unhealthy) |
| flaccidity(noun, weak, sick, unhealthy) |
| foible(noun, weak, sick, unhealthy) |
| forward(adjective, close, open, free, easy) |
| fragility(noun, weak, sick, unhealthy) |
| frailty(noun, weak, sick, unhealthy) |
| frangibility(noun, weak, sick, unhealthy) |
| free(adjective, close, open, easy, friendly) |
| free-and-easy(adjective, close, open, free, easy) |
| freeze |
| friendly(adjective, close, easy, relaxed, comfortable) |