1. n. A fictional creature from the Harry Potter series. Dementors guard the wizard prison Azkaban and suck all of the happiness from anything in their presence. Their worst weapon is called the dementor's kiss, which is when a dementor sucks a person's soul out through their mouth.
2. n. A person who kills a good moment or sucks all of the fun out of a situation.
1. "Dementors are among the foulest creatures that walk this earth. They infest the darkest, filthiest places, they glory in decay and despair, they drain peace, hope, and happiness out of the air around them."
2. Robert: Wow I hate going to parties with Erin, she's such a dementor.
Nathan: I know, all she does is stand in the corner and frown...
The Dementor is a sex position where you assume the misonary position. You then place the blankets over your head like a Dementor from Harry Potter and push down on her stomach, taking all her breath away. It is at this moment you must climax and then make the high pitch squeel of a Dementor. If said female then yells "expecto patronum" well, then you marry her.
While kissing french or otherwise, one partner will suck the air (soul) out of the other partners mouth and lungs. Also effective in sucking the happiness out of the room.
Steve: If I know I'm not getting any with a girl, I'll give her a Dementor's Kiss.
Dave: What?
Steve: I'll kiss her so I can suck all the air out of her and kill the mood even more.
In the Harry Potter series there is a creature called a dementor that is used to guard the wizarding prison of Azkaban. Their special power is the ability to take the joy away from anyone they are near and their most lethal attack is the "dementor's kiss" where they can suck the soul out of a person.
This term can also refer to a case where a poor unsuspecting dude in a bar locks lips with the ugliest broad there. This can either be done by force or with the aid of beer goggles. The result is that he feels miserable and disgusted with himself. Quite like having one's soul sucked out.
"Dude! Dude! I saw thatold hag give you the dementor's kiss. You ok?"
"duuuude I'm so ugh so *hiccup* wasted I couldn't even defwend meself."
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.