Green’s Dictionary of Slang

1. (US black) a white man.

1965		C. Brown Manchild in the Promised Land (1969) 347: That’s the same thing Mr. Chuck’s been doing all these years.
1972		J.A. Williams Capt. Blackman 17: Knew it all the time [...] Chuck ain’t shit. Talk about the Devil!
1972		B. Rodgers Queens’ Vernacular 63: chuck-lover (pej, black gay sl, fr black sl Charley = the white man) black man who prefers white sex partners.
1987		(con. 1967) Bunch & Cole Reckoning for Kings (1989) 141: These chucks [...] still gonna think you a nigger.
1990		(con. c.1970) G. Hasford Phantom Blooper 23: I no longer choose to participate in the mindset of morally disoriented bloodthirsty chucks.
2000		Other Side of the Wall: Prisoner’s Dict. July 🌐 Chuck: A white prisoner or officer. (MI).

2. (US black) a man.

2010

A. Steinberg Running the Books 82: A bitch like me can't be stuck on chuck, the boss is lost, for nada.