When a boy seems very good looking when in fact they only appear this way because no one else in the room is good looking. Therefore, by comparison he is a looker.
Girl: That guy over there is so good looking.
Girl2: I think it's only a bit of the Only Boy Syndrome going on. Look at everyone else here.
*looks around realizing everyone else is unfortunate looking*
Girl: I think your right...damn
When someone is bringing you down, getting on your nerves with their negativity, being an all round annoyance due to their lack of enjoyment of life.
Also can be said as "Deb" "Debster" or "The Deb"
God why is she being such a Debbie?
Last night she was such a Deb.
SHe said she was going to drive us last night but then the Debster came out to play and we had to take a taxi
The Deb made an apperance last night, what a bummer.