When you stop someone from having sexual relations with a member of the opposite sex. Commonly used so you dont have to call your girlfriends best friend a cock block in front of her.

Rooster= cock, Wall=block

see cock block
Man 1: I almost got in my girls pants but her friend kept calling so we had to leave to pick her up.
Man 2: Damn. Rooster Wall-ed
by George Tedd December 28, 2010
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A more PC term for "cock-block"
Yeah, last night at the dinner party Maxwell was being a complete rooster wall.
by Deacon of the Desert Drive-By December 4, 2007
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