when you go beyond a normal erection and your penis has hardness of stone.
i had major rock cock after walking in on your mom in the shower.
by tyler0durden June 27, 2005
After a concert when a girl gets layed by a rock band member, preferabley on the bands bus.
"That lead singer is hot as hell, I'm getting me some ROCKCOCK tonight"
by Parma-lay-me June 13, 2009
your cock rubs against small to large jagged rocks thus producing a reddish inflammed penis.
The water is low today for tubing I hope i dont get rock cock on the rapids.
by meaty petey June 12, 2011