Green’s Dictionary of Slang

1. of a woman, lecherous, lascivious, thus as n.

1682–3		Ten Pleasures of Marriage in (DSUE).
1882		Cremorne I 28: The cook, Dolly, is a hot-arsed a bitch as any wench in the county.
1888–94		‘Walter’ My Secret Life (1966) II 313: She was getting hot-arsed and she lined the poking. [Ibid.] III 606: I quite longed to see this hot-bummed, cunt-neglected wife [Ibid.] VI 1154: She is such a hot-cunted little devil, that God knows what she’ll be up to.
1952		J. Jones From Here to Eternity (1998) 221: Went on the bum, instead of finding him a good hotassed wench and settlin down.
1959		P. Marshall Brown Girl, Brownstones (1960) 31: ‘You know every Sat’day he does run bird-speed to the concubine.’ [...] Virgie roared her disapproval. ‘Nobody din say he can’t have the hot-ass woman but, c’dear, his own got to come first.’.
1968		D. Dee Golden Betty 9: The close proximity of a hot-assed bitch.
1970		E. Thompson Garden of Sand (1981) 15: What did that hot-assed little bitch know?
1985		‘Thommo’ Dict. Aus. Swearing & Sex Sayings 69: HOT ARSE — A young girl, or mature woman, who has nymphomaniac tendencies, or is excessively sexually excitable.
1998		G. Burn Happy Like Murderers 79: Her brother-in-law [...] called her a ‘hot-arsed little sod’.

2. in fig. use, exciting, stimulating.

1978

J.D. Barber Race for the Presidency 161: But John Lindsay views the gaffe scene less sanguinely: ‘Some nice rational guy has a hotassed conversation with the candidate—and rushes off’ [excitedly].