Green’s Dictionary of Slang

1. the act of fellatio.

1940		cited in Lighter HDAS I.
2002		Sandmann ‘Burning Down the House’ Planet Sex Stories 🌐 If you haven’t guessed it by now, I can tell you that I’m a real cocksuck queen. It’s not just that I have great technique, which I do, but I also just love slurping on a dick.

2. a general term of abuse.

1977		(con. 1969) M. Herr Dispatches 138: Hey, cocksuck, you just tol’ me to turn it off.
1981		J. Ellroy Brown’s Requiem 73: Freshly painted obscenities covered the back wall near the workbench: ‘fuck’, ‘cocksuck’, ‘kill fuck,’ and ‘cocksuck bastard’.