Green’s Dictionary of Slang

(US black) a fool.

1928		C. McKay Home to Harlem 26: Oh, Jakie, Jake! What a big Ah-Ah you is.
1929		W. Winchell On Broadway 3 Aug. [synd. col.] The ah-ah who gets carbonated on your giggle water and then proceeds to give you a piece of his mind.
1931		N. Van Patten ‘Vocab. of the Amer. Negro’ in AS VII:1 26: What a big ah-ah I was.