The lady's love idol (4)
I believe the answer is:
hero
'idol' is the definition.
(thesaurus)
'the lady's love' is the wordplay.
'the lady' becomes 'her' (I've seen this before**).
'love' becomes 'o' (In tennis, 'love' means 'zero').
'her'+'o'='HERO'
(Other definitions for hero that I've seen before include "Valiant man" , "girl a ring" , "Lamp-lighting lover" , "Exemplar" , "Person distinguished by exceptional courage" .)