Green’s Dictionary of Slang

jingle-jawed adj.

(US) talkative.

Wash. Bee (DC) 16 Feb. 1/3: There isn’t public spirit enough among this community of jingle-jawed grumblers and fault finders to get up a meeting.
Minnesota Farmers’ Instit. Annual 12-13 28: Most any jingle-jawed creamery agitator can build creameries on farmers’ autographs, but it takes cows to run ’em.
Mag. Fantasy & Science Fiction 68:1-3 34/1: A mulatto-looking Italian boy was reviving the 1860s U.S. Civil War with a jingle-jawed Kentucky plow-boy.