Top Irish accent for a scoundrel (5)
I believe the answer is:
rogue
'for a scoundrel' is the definition.
(rogue is a kind of scoundrel)
'top irish accent' is the wordplay.
'top' means to remove the first letter.
'irish accent' becomes 'brogue' (I've seen this before).
'brogue' with its first letter taken away is 'ROGUE'.
(Other definitions for rogue that I've seen before include "Diverging from type" , "Baddy" , "Unprincipled man" , "Scally" , "Bad guy" .)