Green’s Dictionary of Slang

q adj.

homosexual.

1948		K. Williams Diaries 26 Jan. 20: I asked Ced. if he knew Socrates and Terry were q. and he said he did! [Ibid.] 5 Mar. 24: Camp conversation with Marie — she says Cyril Ritchard is queue!!! I was really amazed!
1952		K. Williams Diaries 16 Sept. 80: To Elstree to play Window dresser in film Innocents in Paris [...] Dreary business. Masses of q. degenerates.
1972		B. Rodgers Queens’ Vernacular.
1989		Kirk & Madsen After The Ball 258: ‘Q-types’ – homosexuals on display. Q’s don’t wish to be seen as straight.

In phrases

go queueing (v.)

to live as a homosexual.

1948

K. Williams Diaries 16 Mar. 25: Met Michael Berry today [...] and he is a female impersonator! The whole thing seems to be a conspiracy! Is the whole of London going queue-ing?