A heartless lie, trouble for lover (10)
I believe the answer is:
aficionado
'lover' is the definition.
(I've seen this before)
'a heartless lie trouble' is the wordplay.
'heartless' means to remove the middle letters.
'lie' becomes 'fiction' (I've seen this before).
'trouble' becomes 'ado' (I've seen this before).
'fiction' with its centre removed is 'ficion'.
'a'+'ficion'+'ado'='AFICIONADO'
'for' acts as a link.
(Other definitions for aficionado that I've seen before include "freak" , "Informed enthusiast" , "supporter" , "Expert person" , "Devotee" .)