Green’s Dictionary of Slang

(US) talkative, garrulous.

1883		J. Hay Bread-Winners (1884) 75: He hated these ‘chinny bummers,’ as he called them, who talked about ‘State help and self-help’ over their beer.
1899–1900		C.L. Cullen Tales of the Ex-Tanks 46: This chinny sport jumped up and yelled [etc.].