Green’s Dictionary of Slang

1. a general phr. indicating either that one has failed to hear a speaker or finds it hard to believe the statement, ‘please repeat yourself’, ‘could you say that again?’, ‘you must be joking’.

1903		Ade People You Know 122: ‘Come again,’ said the Wage Earner.
1911		T.A. Dorgan in Zwilling TAD Lex. (1993) 55: Come again I don’t make you.
1916		A. Stringer Door of Dread 7: ‘What nationality are you?’ ‘Come again,’ said the puzzled girl.
1944		Cab Calloway New Hepsters Dict. in Calloway (1976) 254: come again (v.): [...] I don’t understand you.
1949		(con. 1943–5) A. Murphy To Hell and Back (1950) 60: ‘Front-line slovenliness [...] will not be tolerated in this area.’ ‘Come again’, says Snuffy.
1959		W. Hall Long and the Short and the Tall Act I: bamforth: Tuesdays and Wednesdays he’s going steady with an Eisteddfod. / smith: Come again?
1960		‘Nino Culotta’ Cop This Lot 140: ‘You savvy our lingo pretty good. How’d yer come ter latch onto ut?’ ‘Come?’.
1963–74		B. Humphries Barry McKenzie [comic strip] in Complete Barry McKenzie (1988) 14: Come again? What’s up?
1975		D. Nobbs Fall and Rise of Reginald Perrin (1976) 18: ‘Cup of char and a wad,’ he said. ‘Come again?’ said the proprietor.
1983		A. Payne ‘Senior Citizen Caine’ in Minder [TV script] 37: Come again?
1999		Observer Rev. 12 Dec. 16: Come again, Tony?
2001		K. Waterhouse Soho 23: ‘Why do you say she gave you the Spanish fiddle?’ ‘Come again?’ ‘Spanish fiddle. El bow.’.

2. (W.I./UK black teen) a call to the disc jockey to replay a piece of music.

2004		posting at www.tampaforums.com 23 July 🌐 Who wants the rewinds, Some noise for the rewind... Will up and come again selecta.
2008		record review at www.gospelreggae.com 🌐 Hey wait a minute, let me hear that Monty track again – Wheel and come again selecta!