Mafia boss with term in prison - he's emasculated (5)
I believe the answer is:
capon
'he's emasculated' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'mafia boss with term in prison' is the wordplay.
'mafia boss' becomes 'capo' (head of a crime syndicate).
'with' is a charade indicator (letters next to each other).
'term in' indicates one should take the final letters (term can mean the end of something).
The final letter of 'prison' is 'n'.
'capo'+'n'='CAPON'
Can you help me to learn more?
(Other definitions for capon that I've seen before include "Male fowl fattened for eating" , "Castrated cock fattened for eating" , "Castrated cock fowl" , "Emasculated fowl" , "A tasty bird" .)