to talk without cessation, to scold vehemently.
jaw. One of the two bony structures of the mouth in which the teeth are set.

Speech, discourse. Give us none of your jaw; let us have none of your discourse. A jaw-me-dead; a talkative fellow. Jaw work; a cry used in fairs by the sellers of nuts.
speech, or talk; “hold your jaw ,” don't speak any more; “what are you jawing  about?” i.e., what are you making a noise about?

jaw should not be used as a synonym for “mouth” or “talk.” Such expressions as “Hold your jaw”; “Shut your jaw,” and “What are you jawing about?” have no place in the vocabulary of persons of refinement.