Men's hairdresser (6)
I believe the answer is:
'men's hairdresser' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for barber that I've seen before include "Hair trimmer" , "who performs on the fringe?" , "Hairdresser who cuts and shaves" , "one to profit from the cuts?" , "producing various versions of Hair?" .)