Green’s Dictionary of Slang

1. cowardly.

1934		H. Roth Call It Sleep (1977) 282: Shittin’ fraid-cat, me! Scared now. Never was.
1970		E. Thompson Garden of Sand (1981) 188: I’m tellin you [...] all of you, Mister Roosevelt and the whole shittin shebang, once and for all – I QUIT!
1993		I. Welsh Trainspotting 155: The beggar Boy [...] calls us aw the shitein cunts under the sun.
2000		N. Griffiths Grits 82: Larst fuckin twat ad call on in-a scrap ud be tha shitein twat.
2018		I. Welsh Dead Man’s Trousers [39]: — Uncuff ays, ah say, nearly in a whisper. — A fuckin square go then, ya shitein cunt.

2. a general term of abuse.

1951		K. Amis letter 22 Dec. in Leader (2000) 267: Here I am and here I bloody fucking bastard buggering sodding pissing shitting stay.
1961		L. McMurtry Horseman, Pass By (1997) 79: You mean to try an’ pass this shittin’ stuff off on some old boy.
1971		(con. WWII) B. Aldiss Soldier Erect 9: The humiliation – the ignobility - of the whole shitting shower.
1974		(con. 1940s) E. Thompson Tattoo (1977) 28: Same shittin thing with your paper route and them fried pies.
1983		S. King Christine 222: Those shitting insurance companies are all rich as Croesus, but they won’t cover you unless the odds are stacked outrageously in their favour.
2015		I. Welsh Decent Ride 174: Eh’s a fuckin shitein cunt really.

3. as an intensifier.

1966		G. Fletcher Down Among the Meths Men 50: Aw, yus, shut that shittin’ sod hup.
1987		(con. 1968) Bunch & Cole Reckoning for Kings (1989) 292: More shitting Bacardi in that than they got in all of Cuba.