Green’s Dictionary of Slang

a dandy, a ‘swell’.

1794		Sporting Mag. Aug. IV 288/2: Odd dickies, queer kids, and rum codgers.
1889–90		Barrère & Leland Dict. of Sl., Jargon and Cant.
1890–1904		Farmer & Henley Sl. and Its Analogues.