Green’s Dictionary of Slang

a male homosexual.

2001		Luke’s Domain 14 Nov. 🌐 The wonderful things $10,000 a year can teach a person. Such as: calling a person an ‘Anal Astronaut’ is wrong. While having non-consenting anal sex with the cheerleading squad is sometimes acceptable.
2001		D. Looser Boobslang [U. Canterbury D.Phil. thesis] 7/1: anal astronaut n. (also anal avenger) a homosexual.