Green’s Dictionary of Slang

1. (also tom it) of a black person, to act in an inferior and obsequious manner to whites, to act as a black stereotype; thus tomming n.

1950		Pittsburgh Courier (PA) 4 Mar. 20/1: We who take part in [Mardi Gras] just ‘Tom’ all over the scene.
1954		(con. 1920s–30s) J.O. Killens Youngblood (1956) 345: You made the worst kind of an uncle tom out of me, and you didn’t do such a bad job of tomming yourself.
1961		New Yorker 23 Sept. 101: The materials include offensive Uncle Tomming.
1963		L. Bennett Jr ‘The Convert’ in King Black Short Story Anthol. (1972) 161: ‘They say you are going to chicken out, Papa.’ ‘Chicken out? What that mean?’ ‘They’re betting you’ll “Tom”.’.
1966		N.Y. Times 5 Mar. 25: The whole gamut of Negro behavior [...] involves one form or another of ‘Tomming it:’ being like Uncle Tom.
1967		Babs Gonzales I Paid My Dues 49: I ‘Tomed’ for him and explained we were only listening to records.
1971		New Yorker 6 Nov. 172: She was an absolutely direct black woman. No Tomming, not a shade of the phony to her.
1980		E. Folb Runnin’ Down Some Lines xviii: They jus’ black people, tommin’ fo d’ white folks. [Ibid.] 27: Niggers bein’ niggers, ain’t Tommin’ fo’ no white folks – cain’t be doin’ that shit no mo!
1990		N. George ‘Forty Acres and an Empire’ in Buppies, B-Boys, Baps and Bohos (1994) 112: Blasting [...] Arsenio Hall’s tomming.
1996		Eble Sl. and Sociability 82: Uncle Tom for ‘a black who is overly subservient’ is widely known to be from the title character of Harriet Beecher Stowe’s novel, but its shortened form tom, particularly when it functions as a verb, is marked as black usage.

2. to toady.

1969

H. Rap Brown Die Nigger Die! 119: They were tomming worse than negro Toms. And you ain’t seen no Toms until you see white folks tom. It was ‘Mr. Brown this’ and ‘Mr. Brown the other.’.

3. (also tom out) to betray, to inform; thus tomming n.

1969		H. Rap Brown Die Nigger Die! 14: You had to excel in either fighting, running or tomming.
1976		Eble Campus Sl. Nov. 5: tom – to tell on someone.
1980		E. Folb Runnin’ Down Some Lines 47: If he get busted — then he’ll tom out on everybody. [Ibid.] 258: tom out Inform the police about the actions of another black.