"Borstal Boy" author (5)
I believe the answer is:
behan
'borstal boy author' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for behan that I've seen before include "Brendan...wrote ''The Quare Fella'' (5)" , "Irish writer?" , "Brendan - - (Irish lit.)" , "Brendan - - , playwright" , "Brendan ---, Irish dramatist" .)