Green’s Dictionary of Slang

1. using the lavatory.

1940

D. Maurer Big Con 185: In the course of certain solemn rites enthroned.

2. (gay) searching for sex in public lavatories [+ a pun on queen n. (2)].

1941		G. Legman ‘Lang. of Homosexuality’ Appendix VII in Henry Sex Variants.
1965		Guild Dict. Homosexual Terms 14: enthroned (adj.): In a public toilet; said most often of tearoom queens.
1972		B. Rodgers Queens’ Vernacular.
2010		W. Ings ‘Trolling the Beat to Working the Soob’ in Int’l Jrnl Lexicog. 23:1 65: If he was in a cubicle for a lengthy period of time he was enthroned.