late 14c., "the bones of the mouth," perhaps from Old French joue "cheek," from Gaulish *gauta "cheek," or perhaps a variant of Germanic words related to chew (q.v.); cf. also jowl. Replaced Old English ceace, ceafl.
1610s, "to catch in the jaws, devour," from jaw (n.). In slang from 1748, "to gossip, to speak" 1810, "to scold." Related: Jawed; jawing. Hence 19c. U.S. slang jawsmith "talkative person" (1887).