He's wicked and may be fined (5)
I believe the answer is:
fiend
'he's wicked' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'may be fined' is the wordplay.
'may be' indicates anagramming the letters.
'fined' anagrammed gives 'FIEND'.
'and' is the link.
Can you help me to learn more?
(Other definitions for fiend that I've seen before include "Evil supernatural being" , "Evil spirit, demon" , "Wicked and inhuman person" , "Demon, ogre" , "monster" .)