Green’s Dictionary of Slang

beat one’s gums v.

also beat one’s chops, ...lip, beat on one’s chops, beat up one’s chops, …gum(s), beat up the chops, ...gums, bat one’s gums, chop one’s gums,flap one’s gums, …teeth, smack one’s gums
[SE beat + chops n.1 (1)//SE gums/SE lips]
(US)

1. to chatter, to talk, esp. in an irritating manner.

[US]Charleston (WV) Daily Mail 21 July 6/8: If you heard a Negro saying that his gal is ‘always beatin’ her chops in off time’ you might not know that he was complaining of her penchant for gossip.
[[US]New Yorker 15 46/2: Quit beating your gums together, Papa Houdini, and help me out with a drink].
[US]Leatherneck 27:11 30/2: He kept beating his gums about her all day.
[US]Cab Calloway New Hepsters Dict. in Calloway (1976) 253: beat up the chops (or the gums) (v.): to talk, converse, be loquacious.
[US]Mezzrow & Wolfe Really the Blues 48: I stood around outside the Pekin, beating my chops with Big Buster.
[US](con. early 1930s) C. McKay Harlem Glory (1990) 79: Niggers will beat up their gums, for all they can do is talk.
[US](con. 1944) N. Mailer Naked and Dead 244: Conn was probably still beating his gums.
[US]Kerouac letter 16 Mar. in Charters I (1995) 143: The farmers were chewing the fat in feed and hardware stores, the women were chopping their gums in Five-and-Tens.
[US]L. Uris Battle Cry (1964) 291: The squad, sitting about, beating their gums.
[US]Murtagh & Harris Cast the First Stone 108: You’re not just beating your lip [...] Doggone right.
[US]Hughes & Bontemps Book of Negro Folklore 481: beat up your chops: Talking a lot. Stop beating up your chops, gal.
[UK]A. Salkey Quality of Violence (1978) 93: You can stay and beat up you’ gum, if you want. I not listening no more.
[US]‘Lord Buckley’ Hiparama of the Classics 14: The Cat is still up there beatin’ on his chops.
[US] (ref. to WWII)Wentworth & Flexner DAS 22/1: bat one’s gums To converse; to talk idly but volubly; to chat.
[US]Wentworth & Flexner DAS 103/1: chop [one’s] teeth To talk idly; to interject unnecessary remarks into a conversation.
[US](con. 1940s) M. Dibner Admiral (1968) 255: Another shot, Fatty, and quit beating your gums.
[US]C. Himes Blind Man with a Pistol (1971) 152: Wonder the big boss ain’t beating up his chops about that ain’t the right way and crime don’t pay.
[US](con. 1960s) D. Goines Black Gangster (1991) 266: If all you goin’ do is beat your gums about it.
[Aus]C. Bowles G’DAY 58: Mrs Foster and Shirl sit down and start flapping their gums, and Jason .is left in charge of cooking the snaggers.
[US]D. Gaines Teenage Wasteland 63: That’s the art of street hang. Telling stories, throwing the bull, smackin’ your gums.

2. to talk in a melodramatic manner.

[US]Z.N. Hurston ‘Story in Harlem Sl.’ in Novels and Stories (1995) 1002: Last night when I left you, you was beating up your gums and broadcasting about how hot you was.
[US]H. McCoy Kiss Tomorrow Goodbye in Four Novels (1983) 98: Ain’t that just like cops? Always beating their gums.

3. to eat.

[US]N. Algren Man with the Golden Arm 91: Stash beat his gums around the evening pumpernickel.

4. to complain.

[US] in T.I. Rubin Sweet Daddy 58: I mean I dig anywhere. No use beating your chops.

In exclamations

beat your gums!

don’t talk rubbish!

[US](con. 1950) E. Frankel Band of Brothers 1: ‘Three months out of P.I. and you’re a real old salt!’ ‘Beat your gums!’.
[UK]V. Bloom ‘Name Shame’ in Touch Mi, Tell Mi 19: Soh dem can tan de beat up dem gum, / For dem noh how nutten go.