半翅目：一目有翅或无翅的昆虫，包括普通的臭虫和虱，特征为有能刺入或吸吮的口器。异翅亚目(Heteroptera)中的臭虫科(Cimicidae)和猎蝽科(Reduviidae)有许多医学上重要的种属- flexion
- Flexner's bacillus, dysentery, serum
- flexor
- flexorplasty
- flexuose
- flexura
- flexurae
- flexural
- flexure
- flicker
- flight of ideas
- Flint's arcade, law
- Flint's murmur
- floaters
- floccilegium
- floccillation
- floccose
- floccular
- flocculation
- floccule
- flocculent
- flocculi
- flocculoreaction
- flocculus
- floctafenine