Boy seen in bazaar once (5)
I believe the answer is:
aaron
'boy' is the definition.
(I've seen this before)
'in bazaar once' is the wordplay.
'in' indicates the answer is hidden within the clue.
'AARON' is hidden within 'bazaar once'.
'seen' acts as a link.
(Other definitions for aaron that I've seen before include "Brother of Moses who founded the Jewish priesthood" , "- - Copland (mus.)" , "OT character" , "Boy" , "Brother of Moses, led the Jews to the Promised Land" .)