Green’s Dictionary of Slang

1. (US) a form of highly suggestive belly-dance, usu. performed at carnivals; usu. attrib.; thus kootcher, a dancer (cf. cooch n. (1)).

1924		(con. 1880–1924) F.J. Wilstach Anecdota erótica 35: Old man [...] was invited to a stag party. On arrival he discovered there were naked women doing kootch dances.
1946		W.L. Gresham Nightmare Alley (1947) 17: There was a Hawaiian dance show, what they called a kooch show.
1954		(con. 1941) C. Chessman Cell 2455 196: We were wobbling and bouncing along in what most appropriately can be described as a remarkable rendition of a vehicular kootch dance.
1966		R.E. Alter Carny Kill (1993) 11: I [...] joined the gang of lusty-eyed marks in front of the kootch bally stand.
1975		J. Roe The Same Old Grind 37: I couldn’t raise him [e.g. a baby] right, being a kootch girl in a carnival.
1979		S. King Dead Zone (1980) 28: They passed a kootch joint. Three girls stood out front in sequined skirts and bras. They were shimmying to an old Jerry Lee Lewis tune.

2. the vagina; thus a prostitute.

1971		L. Bangs in Psychotic Reactions (1988) 8: I got a date with Delilah Kooch tonite.
1994		(con. 1941) A. Kernan Crossing the Line 97: One of the officers was keeping a kootch, a local whore, in a cabin down in the bushes.
1997–2000		College Sl. Research Project (Cal. State Poly. Uni., Pomona) 🌐 Kochee {vulgar} (noun) A female’s genitals. [...] Kooch {vulgar} (noun) Vagina.

3. (US gay) the anus.

1972

B. Rodgers Queens’ Vernacular 19: the rectal opening, anus [...] kootch.