Green’s Dictionary of Slang

a skilful person, an expert.

c.1698		B.E. Dict. Canting Crew n.p.: Dab, expert, exquisite in Roguery [...] He is a Dab at it, He is well vers’d in it.
1711		Vindication of H. Sacheverell 83: The Dr. is charg’d with being a great Dab, as the Boys say.
1725		New Canting Dict. [as cit. c.1698].
1733		Lord Chesterfield Letter 17 Aug. Suffolk Correspondence (1824) II 64: A faithful copy of it was to be transmitted to others of not inferior abilities, and known dabs at finding out mysteries .
1748		Dyche & Pardon New General Eng. Dict. (5th edn).
1753		J. Poulter Discoveries (1774) 32: You are a Dab, I will not lay you any more.
1762		O. Goldsmith Life of Richard Nash in Coll. Works (1966) III 349: You are a dab, I will not lay with you.
1772		Bridges Burlesque Homer (3rd edn) 151: He understood the art of fighting, / But was a greater dab at biting / His neighbour’s head off in a bargain.
1783		‘Peter Pindar’ ‘Lyric Odes’ Works (1794) I 73: At calling names I never was a dab.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1800		‘Physical Snob’ in Jovial Songster 9: There’s no greater dab at the job, Sirs.
1811		Lex. Balatronicum.
1819		‘One of the Fancy’ Tom Crib’s Memorial to Congress 1: The dab’s in quod; the rogue is in prison.
1820		‘Peter Corcoran’ Fancy 5: Montgomery is no dab at a bull-bait.
1832		Egan Bk of Sports 19: The accountant-general, who was a dab in figures.
1844		T. Hood ‘Masonic Secret’ Works (1862) VII 27: To be sure we mayn’t be quite such dabs at chiselling and levelling.
1853		Dickens Bleak House (1991) 342: I have had French women come before now and show themselves dabs at pistol-shooting.
1863		T. Moser Mahoe Leaves 88: Smith, who had been some time in China [...] was a ‘dab’ at ‘Canton English’.
1870		Hotten Sl. Dict.
1873		M.E. Braddon Strangers and Pilgrims II 269: I’m not a dab – I mean I’m a poor hand at penmanship.
1884		Ally Sloper’s Half Holiday 14 June 50/149: Everybody almost, on his own showing, is a dab at something or other.
1885		Bulletin (Sydney) 7 Mar. 16/1: They are all Australian natives, young fellows in the prime of health and spirit, and Mr. Shipway has been known for several years past as the crack amateur walker of the colony and a ‘dab’ at athletics generally.
1895		Truth (Sydney) 10 Mar. 1/5: Just hand me the Book, / I’m a dab at the Service.
1896		E. Pugh Man of Straw 93: I’m no dab at talk like you, Miss Eva.
1900		Boys Of The Empire 11 Dec. 151: Are you a dab at batting?
1902		‘Dads Wayback’ in Sun. Times (Sydney) 27 July 10/1: ‘Jimmy is er dab at-clearin’ [land]’.
1914		Bulletin (Sydney) 5 Nov. 13/2: Young Jone’s capacity for soaking up knowledge is something to marvel at. He is a dab at English; he attends the law courts to pick up shorthand, and his mathematical accuracy is an object-lesson.
1914		Sport (Adelaide) 24 July 4/2: A,W. kids he is getting a dabby at dancing now .
1916		‘Anzac’ On the Anzac Trail 47: The newspaper sellers were real dabs at learning English.
1922		Joyce Ulysses 272: Molly great dab at seeing anyone looking.
1940		M. Marples Public School Slang 56: dab, (1) a clever boy (Christ’s Hospital, 1908 +), an expert; also dab-hand, dabster.