Definitions by Chas Picklewater

Clam Dam 

To interfere with a female who is getting acquainted with, conversing with, or hooking up with a person of sexual attraction

The feminine form of "cock block"

At the Halloween party, Melissa was about to get Kevin's phone number, when Seth clam dammed her by asking him if she found a job yet. He made it even worse when he reminded Melissa that they had to hurry up and catch the last bus home. Feeling awkward, Kevin walked away as soon as he had the chance.

Clam Dam by Chas Picklewater November 29, 2007