Green’s Dictionary of Slang

1. (also old chappie) a man; also as a term of address; also attrib.

1821		‘An Amateur’ Real Life in London I 183: Come, ould chap, vet your vistle and tip it us rum—go it my kiddy, that are’s just vat I likes.
1837		‘The Two Butlers’ in Bentley’s Misc. Mar. 308: ‘I say,’ said he ‘old chap! is this castle to be seen?’.
1848		G.W.M. Reynolds Mysteries of London II (2nd series) 24: Well, now – it can’t be done, old chap.
1879		G.R. Sims Dagonet Ballads 70: I heerd ’em, old chap, what they sed.
1884		‘’Arry at a Political Pic-Nic’ in Punch 11 Oct. 180/1: Don’t ketch me a-slinging my legs about arter a beast of a ball / At ninety degrees in the shade or so, Charlie, old chap, not at all.
1899		E.W. Hornung Amateur Cracksman (1992) 22: I’m sorry you weren’t there too, Bunny, old chap.
1900		Boy’s Own Paper 15 Dec. 166: ‘Stick close to me, old chap,’ said Bates.
1906		Marvel 10 Mar. 171: You’ll find that tobacco a beastly good brand, old chappie.
1914		Joyce ‘A Little Cloud’ Dubliners (1956) 77: Thanks awfully, old chap.
1916		Firefly 9 Dec. 1: So off I waddled, leaving the old chap to enjoy the draft!
1922		Wodehouse Clicking of Cuthbert 46: What did you do then, old chap?
1938		F.D. Sharpe Sharpe of the Flying Squad 188: Young men with Oxford accents and ‘Old Chappie’ manners.
1939		V. Davis Gentlemen of the Broad Arrows 53: Sorry, old chap. I know how you feel.
1942		Whizzbang Comics 82: Where have you been buried this last year, old chap?
1953		K. Tennant Joyful Condemned 66: He came down to see the old chap next door.
1971		Wodehouse Much Obliged, Jeeves 60: Oh, hullo, Spode old chap, I mean Lord Sidcup old chap.
1984		A. Sayle Train to Hell 93: Slobbo, old chap, do come.
2000		Guardian Weekend 22 Jan. 22: ‘Frankly, old chap,’ he would say with a smile, ‘there’s a lot of work still to be done on this one.’.

2. one’s father.

1839		in Sanders Juvenile Offenders (1970) 159: He said ‘I’m blessed if they haven’t stuck it into our old chap at last!’ pointing with his thumb to his doomed parent.
1937		J. Curtis There Ain’t No Justice 13: That’ll be the old chap.

3. the penis.

2019

Twitter 8 Nov. 🌐 Rees Mogg swanning around town in a sex offender coat, respecting the war dead by pinning a poppy to his old chap.