1 definition by derek m is gay

Someone who is in the fringe of your group of friends who is tolerated because it would be a shame to tell them to Fuck off!
They also have some strange ability to turn even the funniest momements into akward ones and sap all happiness from those around.
Person 1 : Never invite jim to out for a drink

Person 2 : Why not

Person 1 : Cuz he's a fucking Dementor
by derek m is gay February 26, 2009
Get the Dementor mug.