- falciparumThe parasitic protozoan Plasmodium falciparum that causes falciparum malaria
- falchionA somewhat curved, single-edged medieval sword of European origin, with the cutting edge on its convex side, whose design is reminiscent of the Persian scimitar and the Chinese dao.
- falxA short Dacian sword resembling a sickle.
- falcadeA horse's movement of throwing itself on its haunches two or three times, bending in very quick curvets.
- falcerOne of the mandibles of a spider.
- falcigerA seta that has a curved tip.