Green’s Dictionary of Slang

(UK black) of a male during sexual intercourse, without using a condom, thus n. sex without contraception.

2005		Jade LB Keisha the Sket (2021) 45: i felt him thrust his enormous dick inside me rawbuck.
2005		Jade LB Keisha the Sket (2021) 45: I woz worried as hell. We did da rawbck and he came 3 whole tymz!