a person who truly stops at nothing to prevent another (usually a male) from getting any type of burn.
when sean saw that mahsul was getting too much burn he initiated the cock blocker 3000 (a.k.a Max) who then approched Mahsul and asked him for the hw... while he got it from his bag max began talking to the girl.... max then left with mahsuls hw, his girl, and his dignity.... the encounter ended with mahsul calling max a cock blocker.
by Firekrotch September 27, 2007
One who prevents a guy from banging a girl. Usually a friend or family member, motivated either by jealousy or the fact that they can't get any and don't want to see you get some.
I put the moves on Jane last night but her protective cockblocker brother aggressively cockblocked me and asked me to leave the party as he didn't want me to get any.
by igotcockblocked February 12, 2006