batcave, n. — Green’s Dictionary of Slang

batcave n.

[senses 2 and 3 underpinned by the Batman comics and films, in which the batcave, dark, subterranean and mysterious, is the headquarters where Batman (and Robin) keep their car, their hi-tech weapons and other crime-fighting materiel; also note bat n.² (1), although this is a primarily heterosexual term]

1. (US) a police station and/or its cells [SE batcave].

1899

W.J. Kountz Billy Baxter’s Letters 19: You know I’m not much for the bat cave, and to avoid such after-complications as patrol wagons and things, I blew the bunch and started up street.

2. (gay) the anus.

2003

www.affairsltd.co.uk 🌐 Sex synonyms – anus [...] batcave.

3. the vagina.

2003