Green’s Dictionary of Slang

1. (also bopper) one who dances to bebop tunes.

1948		Life 11 Oct. 139: Boppers go gaga over such bebop classics as Oo Bop Sha Bam, Oop Pop A Da and Emanon.
1993		Tarantino & Avery Pulp Fiction [film script] 39: Wannabe beboppers [...] do the twist in their socks.
1997		(con. late 1950s) A. Frewin London Blues 16: He’s in a suit. One of those striped double-breasted creations the boppers favoured.
2000		(ref. to 1940s) Guardian G2 1 Mar. 19: Melly resolutely championed the old New Orleans sound against those impetuous beboppers.

2. (orig. US black/jazz, also bebop, bopper, bopster) a musician who plays in the bop style.

1947		D. Burley N.Y. Amsterdam News 19 July 17: Her mama [...] rescues her from this bebopper who has yet to play a full chorus with a band.
1948		New Yorker 3 July 28: Boppers call themselves the ‘left wing’ and their opponents the ‘right wing’.
1957		R.S. Gold ‘Vernacular of the Jazz World’ in AS XXXII:4 281: Occasionally [...] bopsters would make a partial concession by playing at weddings and other social functions where musical authenticity is held in low esteem.
1960		Mad mag. June 49: No swinging bopster gigging / Ever yet has piped a rigging like the action near my door.
1961		C. Himes Pinktoes (1989) 45: Two completely gone beboppers avoiding a houseful of squares to blow a marijuana butt.
1965		G. Melly Owning Up (1974) 89: When Humph went mainstream [...] a whole row of the audience raised, during Bruce Turner’s first alto chorus, a long banner reading ‘go home dirty bopper!’.
1967		(con. 1950) Babs Gonzales I Paid My Dues 62: I came second in the ‘best dressed Bopster contest’.
1981		C. Hope Separate Development 114: We’ll go to a jazz session. [...] It’s multi-racial up there at the ’Varsity – they mix. Very cool about colour, those bebops.
2001		Guardian Rev. 9 Mar. 20: The best balance of Davis the cool bebopper and the lyrical Davis was to come with the Blue Note sessions of 1952.
2021		J. Ellroy Widespread Panic 177: She’s [...] out to bang all the bopsters on the ’54 Downbeat [...] polls.

3. (US) a juvenile delinquent [bebop v. (1)].

1966		F. Elli Riot (1967) 43: There were five or six from the glamour-boy clique, weight-lifters and beboppers, their hair combed in duck-tails.
2021		J. Ellroy Widespread Panic 144: I busted beboppers, mud sharks, and junkies [...] in the ’40s.

4. (US black, also beebopper, bopper, diddy-bopper) an inexperienced, naïve and on those grounds unpopular person.

1980		E. Folb Runnin’ Down Some Lines 40: A number of terms [...] characterize this socially out-of-step person, such as bebopper, bopper, diddybopper, teenybopper, jitterbug. [Ibid.] 229: General pejorative for one who is disliked by or different from the speaker.
1987		Eble Campus Sl. Oct. 1: beebopper – trendy person who tries too hard to be fashionable.