When you have sex with a girl, then finish on her vagina. Spread the semen over her vagina and leave it to dry. Once it dries, nothing will get in or out of her vagina, leaving it "beaver dammed"
last weekend i beaver dammed my girlfriend, needless to say she was not happy when she realized what i had done.
by dickfore. March 29, 2010
The "cock block" for the female. When a girl is effectively cock blocked she has been beaver dammed.
She was beaver dammed by her girlfriend when she dropped the herpes word in front of the new guy
by jennyjustjenny December 20, 2012