Rugby thug hit male, held by supporter (8)
I believe the answer is:
flashman
'rugby thug' is the definition.
(Harry Flashman, fictional pupil at Rugby School)
'hit male held by supporter' is the wordplay.
'hit' becomes 'lash' (I've seen this before).
'male' becomes 'm' (common abbreviation).
'held by' indicates putting letters inside.
'supporter' becomes 'fan' (fan is a kind of supporter).
'lash'+'m'='lashm'
'lashm' placed inside 'fan' is 'FLASHMAN'.
(Other definitions for flashman that I've seen before include "Bad guy from Tom Brown's schooldays" , "Bully" .)