Green’s Dictionary of Slang

1. a sexual contortionist.

1939		‘Hotel Sl.’ in AS XIV:3 Oct. 240/2: trapeze artist One who indulges in unnatural intercourse.
1979		Maledicta III:2 232: He also may or may not know the following words and expressions: [...] high russian (both kinds of ‘sodomy,’ anal and oral, simultaneously; it takes a trapeze artist).

2. (US tramp) a tramp who rides the trains.

1930		‘Dean Stiff’ Milk and Honey Route 216: Trapeze artist – A hobo who rides the gunnells or rods.
1949		Monteleone Criminal Sl. (rev. edn).

3. a woman who enjoys cunnilingus, esp. as part of sex exhibitions.

1941

G. Legman ‘Lang. of Homosexuality’ Appendix VII in Henry Sex Variants.

4. (US gay) a fellator.

1972

B. Rodgers Queens’ Vernacular 52: fellator [...] trapeze artist (’40s).