Words of complaint; wrangling, abuse, jabber. “To jaw,” to
annoy with words, to jabber, wrangle, or abuse. The French gueule and gueuler are used in the same manner.
Hold your jaw.
Hold your tongue or jabber. What are you jawing about?
are you jabbering or wrangling about? A break-jaw word.
long word, or one hard to pronounce.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894