Green’s Dictionary of Slang

1. very drunk.

1864

London Standard 13 Dec. 3/3: A higher more intense state of beastliness [...] Out [...] Ploughed [...] Top Heavy.

2. (UK) dead.

1927		(con. WW1) P. MacDonald Patrol 3: ‘He’s out [...] Muriel,’ he said, ‘is napoo. The officer is dead’.
1939		E. Duplesis Cohort of the Damned 7: I let him have four bullets [...] I gave him three in the back of his head for good measure [...] Tough. I felt kind of sorry for him—now that he was out .
1970		L. Sanders Anderson Tapes 115: We want him out—that’s all. You get him out. That’s our price.

3. good, excellent; usu. as superlative outest.

1954		‘Bop Dict.’ Mad mag. Mar. 20: Outest – a-way out, the best.
1954		Mad mag. Nov. 7: Man ... that Caesar was the most and the outest!

4. homosexual [attrib. use of out adv.¹ (2d)].

1992		D. Jarman diary 13 Aug. Smiling in Slow Motion (2000) 192: She was the first out dyke I ever met.
1999		Guardian G2 24 June 2: He was growing in self-dignity as an out gay man.
2003		(ref. to 1950s–60s) Baker & Stanley Hello Sailor! 35: There were many more ‘out’ and active gay people than ever before.