Green’s Dictionary of Slang

(Irish) a contemptible person, often cheeky and foolish.

[1883		A. Easther Gloss. Almondbury 21: Caffler ... a shuffler, excuse-maker, &c].
1896		Dundee Courier 26 Mar. 7/1: The man said: He must be a caffler.
1910		P.W. Joyce Eng. As We Speak It In Ireland.
1932		S. O’Faoláin Midsummer Night Madness and Other Stories 66: Are you going to be stopped by a city caffler?
1951		F. O’Connor Traveller’s Samples 7: Nora came skeltering madly down the church. ‘Lord God!’ she cried, ‘The snivelling little caffler! I knew he’d do it! I knew he’d disgrace me!’.
1961		F. O’Connor An Only Child (1970) 13: Oh, listen to George Crosbie, the dirty little caffler!
1978		T. Hallisey Cork Holly Bough n.p.: ‘You caffler, you scut, you trickie, you tally-boy,’ he roared [BS].
1991		J. Kennedy The People who Drank Water from the River 80: There were the ‘cafflers’ (pranksters) and the straight-laced, the loudmouths and taciturns.
1996		(con. 1950s) C. Kenneally Maura’s Boy 56: Get out of bed, ye caffler, and get down to school.
2001		G. Coughlan Everyday Eng. and Sl. 🌐 Caffler (n): arsehole, idiot, eejit.
2006		K. Bruen Dublin Noir 224: ‘Fecking caffler,’ Mell says, ‘you really have no idea what's going on?’.