Hunk admits vice naughty (8)
I believe the answer is:
devilish
'naughty' is the definition.
(I've seen this before)
'hunk admits vice' is the wordplay.
'hunk' becomes 'dish' (I can't justify this - if you can you should believe this answer much more).
'admits' means one lot of letters goes inside another.
'vice' becomes 'evil' (I've seen this in another clue).
'dish' enclosing 'evil' is 'DEVILISH'.
Can you help me to learn more?
(Other definitions for devilish that I've seen before include "like Screwtape" , "Mischievous; rakish" , "Very difficult to deal with" , "Very wicked" , "naughty" .)