A he-man's girl (5)
I believe the answer is:
helen
'girl' is the definition.
'a he-man's' is the wordplay.
'man' becomes 'len' (short for Leonard).
'he'+'len'='HELEN'
(Other definitions for helen that I've seen before include "Trojan war beauty" , "The Greek army sailed to Troy to get her back" , "She started Trojan War" , "lady" , "Legendary beauty of Troy" .)