bean-jacks, n. — Green’s Dictionary of Slang

bean-jacks n.

[Irish bean, a woman + jakes n.¹]

(Irish) a female public convenience.

1997		Share Slanguage.
2001		G. Coughlan Everyday Eng. and Sl. 🌐 Bean-jacks (n): ladies toilet.
2010		email to boards.ie 19 Mar. 🌐 Mines great. Concrete floors, toilets labeled ‘Jacks’ and ‘Bean-Jacks’ (as in woman in Irish). And if you’re short a few quid, you can buy cans to drink instead of pints.