People that have VERY LARGE CAVEMAN CLUB BETWEEN THERE LEGS!!!
They have very large COCKS hence the word "Denmead"
The prototypical nerd, a person that decreases a positive atmosphere in any room. Someone that may wear their pants above the bellybutton. An individual that enjoys talking about things most people are uninterested in.
"What was wrong with Greg yesterday? He really ruined the party?"
"Yeah he was being such a Denmead."