Green’s Dictionary of Slang

1. a first-rate, admirable thing; an extreme example, negative as well as positive.

1784		G. Colman Yngr song in Hobernian Mag. July 380/2: Her breath is like the rose, and the pretty little mouth / Of pretty little Tippet is the Dandy O!
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: Dandy. That’s the dandy; i.e. the ton, the clever thing.
1787		‘Yankee’s Return’ in S. Foster Damon Yankee Doodle (1959) 8: Marblehead’s a rocky place, / And Cape-Cod is sandy; / Charlestown is burnt down, / Boston is the dandy.
1814		Apollo in N&Q Ser. 6 IX 136: For marriage to old maids is the dandy, O .
1821		R. Waln Hermit in America on Visit to Phila. 2nd series 25: My attention was soon attracted by the voices of the players. [...] ‘It’s all Dickey with you’—‘That’s the dandy’.
1836		‘Jack’s Pipe and Moggy’s Spittoon’ in Gentleman’s Private Songster in Spedding & Watt (eds) Bawdy Songbooks (2011) III 365: She said it would be just the thing, / The tippy and the dandy.
1836		T. Haliburton Clockmaker I 140: What a wappin large place that would make wouldn’t it? It would be the dandy, that’s a fact.
1842		R. Barham ‘Hermann’ in Ingoldsby Legends III (1866) 454: If you wish to ’scape wigging, a dumb wife’s the dandy .
1887		G. Devol Forty Years a Gambler 76: He and his negro left the boat, and I tell you she was a dandy.
1889		Dead Bird (Sydney) 10 Aug. 2/3: A 14st. man tipped him a dandy on the jowl with a fire-shovel.
1894		Herald (Los Angeles) 28 Oct. 9/2: Higgins originated that scheme, and ain’t it a dandy?
1894		Mirror of Life 13 Jan. 15/4: [He] wore a glass eye that was a dandy [...] cost him 700 dols in Paris.
1896		W.C. Gore Student Sl. in Cohen (1997) 19: dandy 1. n. [...] Something that is very good or well done.
1900		T. Dreiser Sister Carrie 95: Eddie Fahrway’s got a new steam launch [...] He says it’s a dandy.
1914		S. Lewis Our Mr Wrenn (1936) 154: ‘Have a good trip?’ ‘Yes, a dandy.’.
1929		M. Levin Reporter 71: Say, I have one for you that’s a dandy! How about a call on the Vice President?
1932		(con. 1919) Dos Passos Nineteen Nineteen in USA (1966) 566: See this car? A dandy ain’t it?
1943		H.A. Smith Life in a Putty Knife Factory (1948) 169: Mrs. Robichaud said she’d quit going to the movies if they didn’t have Westerns, and she told about a dandy she had seen the night before.
1955		E. Hunter Blackboard Jungle 219: ‘You’re joking, but don’t you really like the name?’ ‘It’s a dandy,’ Rick said.
1961		(con. early 1950s) J. Peacock Valhalla 91: I suppose you men had some dandies yourself.
1998		(con. 1960s) G. Washington Blood Brothers 135: It was going to be a real dandy of a story.
2012		T. Robinson ‘Legendary [...] Ralphie O’Malley’ in Dirty Words [ebook] Well, ain’t that just a dandy.

2. an admirable person, a skilful person.

1816		W.T. Moncrieff All at Coventry I ii: In short, madam, I’m the dandy, the thing, the knowing one, the fancy.
1819		Beppo in London lxxiv: Tongues are fluent and expert, When Bilk or Dandy wounds their reputation.
1877		‘Dandy Pat’ in Yankee Paddy Comic Song Book 6: I am from Old Ireland, but what of that, I’m Pat the Dandy O.
1881		Daily L.A. Herald 13 Aug. 2/3: He calls a beautiful woman a ‘lalla,’ a ‘dandy,’ or a ‘corker,’ and an ugly one a ‘chromo’.
1887		World (N.Y.) 26 Aug. 6/4: In the language of that eminent authority Mr. De Wolf Hopper, ‘Mickey Welch is a dandy and the king-pin of them all’.
1889		Dead Bird (Sydney) 24 Aug. 1/4: She was champion of the callisthenic class and a dandy with the gloves.
1893		S. Crane Maggie, a Girl of the Streets (2001) 21: Dat bloke was a dandy [...] but he had’n oughta made no trouble.
1907		C.E. Mulford Bar-20 xi: In about two weeks we’ll have a new marshal an’ he’ll shore be a dandy.
1919		J. Buchan Mr Standfast (1930) 698: You English [...] think a fellow’s a dandy at handling your Government if he happens to have made a pile by some flat-catching ramp on your Stock Exchange.
1928		C. McKay Home to Harlem 30: The dark dandies were loving up their pansies.
1939		‘Flann O’Brien’ At Swim-Two-Birds (1960) 121: Now be damned but hadn’t they a man in the tent there [...] a bloody dandy at the long jump.
1972		D. Jenkins Semi-Tough 205: Some of those T-shirted little dandies with the no-panties and the dinner lungs came up to us.
1979		G. Swarthout Skeletons 235: She’s a dandy, that girl.