Green’s Dictionary of Slang

1. (also slaughter floor, slaughtering floor) anywhere used for the purpose of sexual intercourse.

1962		P. Crump Burn, Killer, Burn! 242: Cool yourself into rigor mortis for not copping righteous on de gismo when you had it on de slaughtering floor. [Ibid.] 303: The broad I took to the slaughter floor this afternoon.
1969		‘Iceberg Slim’ Pimp 68: They were almost stoned. Ready for the ‘killing’ floor.
[1970		San Diego Sailor 47: Bob has a big double bed [...] which I’d nicknamed ‘the battlefield’].
1980		E. Folb Runnin’ Down Some Lines 152: Any place designated for sex [...] killing floor, slaughter house, whip shack.

2. a place where victims are robbed and/or cheated by a confidence trickster.

1979

‘Iceberg Slim’ Airtight Willie and Me 32: The stricken sucker [...] streaked back to the vestibule killing floor.