'Poser' definitions:

Definition of 'poser'

From: WordNet
noun
A person who habitually pretends to be something he is not [syn: poseur, poser]
noun
A person who poses for a photographer or painter or sculptor; "the president didn't have time to be a model so the artist worked from photos" [syn: model, poser]
noun
A particularly difficult or baffling question or problem [syn: poser, stumper, toughie, sticker]

Definition of 'Poser'

From: GCIDE
  • Poser \Pos"er\, n. One who, or that which, puzzles; a difficult or inexplicable question or fact. --Bacon. [1913 Webster] Poseur

Synonyms of 'poser'

From: Moby Thesaurus