Green’s Dictionary of Slang

1. harmless.

1937–84

Partridge DSUE (1984) 6/2: C.17.

2. missing.

1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.
1906		Portsmouth Eve. News 16 July 5/5: ‘Adrift’. William Smithm a stoker, admitted being an absentee from H.M.S. Vernon.
1918		Aussie (France) 8 Oct. 14/2: He told us how he’d been adrift disguised as a sky-pilot for three weeks and was having the time of his life.
1924		(con. WWI) A.G. Pretty Gloss. of Sl. [...] in the A.I.F. 1921–1924 (rev. t/s) n.p.: ad-rift. Absent without leave. Apparently derived from the inference that a soldier who is an illegal absentee is not under the control of the authorities.
1943		‘Henry Green’ Caught (2001) 87: It was only when Eileen sent over to say Mrs Howells had not turned up that Pye knew she was what is known as adrift, that is to say absent without leave, a major crime.
1959		J. Yates-Benyon Weak and the Wicked 51: Words such as [...] ‘jankers’, ‘adrift’ and ‘hatter’ were well-worn synonyms for [...] ‘punishments’, ‘desertion’, and ‘homosexual’.
1960		C. MacInnes Mr Love and Justice 7: A bad discharge-book, too: adrift in Yokohama and repatriated at official expense.
1989		J. Morton Lowspeak.
1991		J.T. Pickle Aus.-Amer. Dict. 3: ADRIFT: Anything that is misplaced. A.W.O.L. in the services.

3. confused.

1937–84		Partridge DSUE (1984) 6/2: C.20. Nautical.
1989		Eble Campus Sl. Sept. 1: adrift – weird, not mentally stable.