crack one out 

To masturbate
see also: wank, frig, toss, tommy-tank, make the bald man cry, choke the money etc etc

John cracked one out in the toilets during his lunch-break.

crack one out by Master Bates September 18, 2003

Crack one out 

To lascerate your cock while 'watching videos of/imagining/looking at photos of/in the presence of' hot sexy women.

Masturbation in laymans terms.

James: "Im going home for a wank."
Tim: "haha, james is gonna crack one out, the randy bastard, remember to clean yourself up, and your mums back, dont be rubbin the cum into her back too much again".

Crack one out by Professor Stupidity March 29, 2008

Crank One Out 

The act of male masterbation and orgasm in a violent fashion.

Tommy Cranked one out all over Susan's face.

Crank One Out by Douglas PerfectHour February 22, 2005