bone, n.⁷ — Green’s Dictionary of Slang

bone n.⁷

[bones n.²; they are also ‘black and white’]

1. (US Und.) a black person.

1935		A.J. Pollock Und. Speaks 11/1: Bone, a negro.
2002		C. Stella Jimmy Bench-Press 78: You ever hear this kid talk? [...] He’s an articulate bone.
2010		(con. 1973) C. Stella Johnny Porno 126: I hope somebody shot this bone after they made the movie.

2. (US black) a person of mixed race, esp. Anglo-Irish-black.

1994

(con. 1940s) C. Major Juba to Jive 52: Bone [...] used during the forties to refer to a person of mixed Anglo-Irish-African ancestry.