When you are about to score with someone and you fuck yourself by saying, "I think we should think about this" or "We are rushing into this too fast" Way to go dumbass!
The inability to watch television between the hours of four o'clock until 5 o'clock, because some member of your family must watch Oprah like its some sort of sick addictive gospel (like a cult).
1) The prevention of a potential hook-up. Either done by a jealous friend/douschebag, or by an overprotective friend (Mother Hen) of the girl involved in potential hook up. (see game killer.
2) The act of "cutting" at a 4-way stop sign and "cock-blocking" someone who has waited thier turn at a stop sign.
1) Guy 1: I'd really like to see you again.
Girl 1: I don't have to go home tonight.
Guy 2: Hey Carl, remember that time you shit yourself?
Girl 1: Ummm... I have somewhere to be...
2) This dumbass in a drivers ed car just cock blocked me at the stop sign. So I tailgated the fucker till he ran of the road, it was my turn at the stop sign, he needs to learn his place.
Preventing a fellow male from tapping ass when hes going downthe stretch. A man can cock block inadvertently but it is often done out of jealousy or asshole-ism.
"That loser couldn't get a chick for himself so he decided to hang around like a third wheel and cock blocked me instead."
At the club, Patrick was about to get Bianca's phone number, when Al (ie the Closer) cock-blocked him by telling her Pat’s a nice guy… that lives at home… with his parents.