Green’s Dictionary of Slang

(US) sexy, exciting.

1929		W. Winchell On Broadway 6 Aug. [synd. col.] The Cy Bartlett-Alice White romance is plenty hot-cha-cha.
1933		Hecht & Fowler Great Magoo 33: You’ve written a song, eh! That’s a hot one! What kind of number is it? Hot-cha?
1944		Jack Lait for W. Winchell 28 Aug. [synd. col.] Billie Kaye [...] head over heels for Pat Myles, the hotcha hatcheck honey.
1950		Dan Burley ‘Back Door Stuff’ 25 Mar. [synd. col.] æScarlet Sister Marys’, red hot mamas [...] hotcha chicks, etc.
1990		R. Gool Cape Town Coolie 15: All those red-hot hotch-hotcha girls – chaps! We must move.
2004		E. Weiner Drop Dead, My Lovely (2005) 87: Confident, healthy, vigorous, [...] with a looker wife and a hot-cha mistress.