look up any word, like hipster:
 
1.
An object, typically a person, that ruins (kills) the mood of those around it.
Often is awkward and doesn't have much self-confidence nor "swag".
Creates an uneasy environment to be in.
Typically does not mesh well with the opposite sex, quite the opposite, actually.
Always making comments that completely throw off everyone's groove.
Party tonight out with the guys going hard, please don't invite flow killer.
by Sick of flow killers December 09, 2010