Green’s Dictionary of Slang

1. a dandy.

1750		Love at First Sight 99: He abhors the Character of a Smart, and his Independency sets him above Artifice.
1753		Scots Mag. 1 Oct. 19/2: I was attended, flattered, and caressed [...] was taken notice of [...] and was universally confessed to be improved into a smart.
1764		Low-life 74: The Jemmies, Brights, Flashes, Puzzes, Pizzes and Smarts of the Town [are] preparing to ride out in fives and sixes.
1781		‘Happy Jerry’ in Bullfinch 14: The best of smarts and flashy dames, / I’ve carried in my wherry .
1782		‘A Country Assizes’ in A. Carpenter Verse in Eng. in 18C Ireland (1998) 406: The clod-pate squire [...] / Swears, drinks and games with puppies, prigs and smarts.
[1791		W. Reeve ‘Tippy Bob’ song in Bluebeard [pantomime] I’m [...] the knowingest smart of the town].

2. used insultingly, a ‘clever’ person.

1913–14		E. O’Neill The Web in Ten ‘Lost’ Plays (1995) 58: Yuh think yuh’re some smart, dontcha, buttin’ in dis way on a guy?
1919		‘Sax Rohmer’ Dope 56: ‘If you two smarts really want handling,’ he rapped ferociously, ‘say the word, and I’ll bash you flat.’.
1969		B. Jackson Thief’s Primer 166: The people who got that money from him are professionals, they’re the type of people that beat the smarts.
1971		B. Short Black and White Baby 86: [A]n Elks Club dinner, one of those small-town smokers where the girls come on later and strip. The M.C. was a stranger, a real show-business smart.
1994		I. Welsh ‘A Smart Cunt’ in Acid House 209: You’re a bit of a smart [...] A smart alec. You think you know all the answers.