Green’s Dictionary of Slang

1. the vagina; thus a woman seen strictly as a sex object.

1947		D. Davin For the Rest of Our Lives 344: He pulls out ten ackers [...] and says it’s hers if she’ll lift up her skirt and give us a shufty at her kush.
1969		‘Iceberg Slim’ Pimp 36: A walking, living, round balloon [...] with a flaming itch for black ‘Cush’.
1972		R.A. Wilson Playboy’s Book of Forbidden Words.

2. sexual intercourse with a woman.

1960, 1975		Wentworth & Flexner DAS.
1966		Trimble 5000 Adult Sex Words and Phrases.