θρίξ
1. "the hair of the head", used by Hom. only in pl.; attic also in sg.; Hom., etc.:—also sheep's "wool", Il.; pig's "bristles", Hom.; οὐραῖαι τρίχες "the hair" of a horse's tail, Il.
2. "a single hair", proverb., θρὶξ ἀνὰ μέσσον "only a hair's breadth" between, Theocr.; ἄξιον τριχός, i. e. good for nothing, Ar.