Green’s Dictionary of Slang

buttocks, behind.

1990		S. Morgan Homeboy 4: Squares gave Rings ’n’ Things a pain in the bahakas.
1993		I. Rankin Black Book (2000) 133: Jock would recognise a racehorse’s bahookey quicker than a human face.
2001		I. Rankin Falls 420: He happened to glance in his rearview and caught the cop car up his bahooky.
2012		(con. 1980s) I. Welsh Skagboys 214: The idea of Simon’ big, fat cock up ma bahookay makes me feel queasy.
2018		I. Welsh Dead Man’s Trousers [18]: Carlotta still has a face on her like a well-skelped bahooky.