definition of
[poser]

[1] #1 poser n. [poseur] a person who habitually pretends to be something he is not. wn

[2] #2 poser n. [model] 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". wn

[3] #3 poser n. [stumper, toughie, sticker] a particularly difficult or baffling question or problem. wn