The incorrect spelling for the word "Poseur". But if you must know, a poser is
(n) Someone who poses for a photograph or a work of art.
Look it up.
Although, a 'poseur', if that is what you meant, is
po·seur pō zúr
(n) A Pretentious Person: somebody who tries to impress others by behaving in an affected way
I'm unsure why people changed the spelling of it, but it is frowned apon. You have just made an ass out of you and me.