Green’s Dictionary of Slang

s.n.a.f.u. adj.

messed up, gone wrong.

1942		C.R. Bond 5 June in A Flying Tiger’s Diary (1984) 183: What a SNAFU operation.
1942		Shields Dly News 4 Sept. 4/6: [headline] Shavetails think that Britain is Snaffoo.
1956		W.A. Heflin US Air Force Dict.
1963		M. Spillane Return of the Hood 19: Now everything was screwed up proper. Real snafu.
1992		R. Marcinko Rogue Warrior (1993) 224: Even the lowliest dogfaces of WWII knew that. ‘How’s it going, soldier?’ SNAFU, they’d say.
1997–2001		Online Sl. Dict. 🌐 snafu adj 1. messed up as usual. Origin: term is an acronym for ‘situation normal, all fucked up.’ (‘Well, that’s typical, they’re just snafu!’).
1998		‘Bill E. Goodhead’ Nubile Treat 🌐 ‘Date didn’t pan out,’ she heard his somber voice reply. ‘I think it’s snafu with Cecilia and me.’.

In phrases

go snafu (v.)

to go wrong.

1949

(con. 1943–5) A. Murphy To Hell and Back (1950) 7: If the landing schedule had not gone snafu, we would have come ashore with the assault waves.