That woman's love for leading man (4)
I believe the answer is:
hero
'leading man' is the definition.
(eg the hero of a film)
'that woman's love' is the wordplay.
'that woman' becomes 'her' (her refers to a woman).
'love' becomes 'o' (love means zero in tennis).
'her'+'o'='HERO'
'for' is the link.
(Other definitions for hero that I've seen before include "Man of great courage and deeds" , "Lion" , "Leander's lover, who committed suicide when he drowned" , "Rochester maybe required?" , "Chief male character in story or film - probably very brave" .)