Villain who's lost half the hair in his head? (6)
I believe the answer is:
pirate
'villain who's lost half the hair in his head?' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'half the hair in his head?' is the wordplay.
'half the' means to take half the letters.
'hair' becomes 'pile' (I've seen this in another clue).
'in his head?' becomes 'rate' (I can't explain this - if you can you should believe this answer much more).
'pile' with half the letters taken is 'pi'.
'pi'+'rate'='PIRATE'
Can you help me to learn more?
(Other definitions for pirate that I've seen before include "Bandit of the ocean, buccaneer" , "Corsair" , "Captain Hook, say" , "Appropriate stuff" , "Rover" .)