Puzzle show-off (5)
I believe the answer is:
poser
I believe this is a double definition.
'puzzle' is the first definition.
(I've seen this before)
'show-off' is the second definition.
(poser is a kind of show-off)
(Other definitions for poser that I've seen before include "Person still being portrayed" , "Ropes (anag.)" , "Tricky question" , "Question - a sitter" , "Artist's model" .)