Green’s Dictionary of Slang

1. incapable of logical thought or speech, feather-brained, eccentric.

1909		W.H. Davies Beggars 205: Nearly all the men that live in common lodging-houses talk to each other in this strain, for they are all more or less short-tempered, or, as they say – ‘scatty’.
1911		J.W. Horsley Memoirs of a ‘Sky Pilot’ 254: Other [words] were new to me, such as [...] ‘scatty’ for mad.
1922		‘J.H. Ross’ Mint (1955) 83: Airmen go scatty when the public calls them ‘Privates in the Air Force’.
1931		O. Strange Law O’ The Lariat 213: That fella’s either loco or not guilty, an’ he shore don’t appear scatty.
1945		‘Henry Green’ Loving (1978) 129: There’s times I could go scatty in this old country.
1950		A. Christie Murder Is Announced (1958) 44: Having appended the word ‘Scatty’ to Dora Bunner.
1961		R.A. Norton Through Beatnik Eyeballs 32: I been scatty to double with a stud I not keen on.
1971		B. Crump ‘Bastards I Have Met’ in Best of Barry Crump (1974) 275: Whimsical, perhaps, even a little faddy [...] dippy, dizzy, giddy, screwy, wacky, scatty or daft.
1985		J. Sullivan ‘Sleeping Dogs Lie’ Only Fools and Horses [TV script] He’s a bloody dog, the scatty mare! Tell her she can’t.
1997		C. Hiaasen Lucky You 66: ‘They say she’s a strange one.’ ‘“Scattered” is the word.’.
2000		Indep. Rev. 18 Feb. 19: Mimi seems unreliable, even mildly scatty.
2001		K. Sampson Outlaws (ms.) 29: None of his scatty-arsed heavy duty blags for no money.
2012		(con. 1980s) I. Welsh Skagboys 86: She went fuckin scatty but.
2015		L. McInerney Glorious Heresies 136: ‘I’m here [...] ‘[t]o spread the word of ... of Jesus Christ.’ ‘You’d think He’d send someone less scatty,’ said the woman.
2023		R. Milward Man-Eating Typewriter 47: [T]he Mare’s scatty visions only worsened.

2. (UK black) failed, performed incompetently.

2020

G. Krauze Who They Was 2: We know it’s [i.e. a robbery] all scatty now, no chance of this being [...] unnoticed .