Note strain for lover (8)
I believe the answer is:
mistress
'lover' is the definition.
(I've seen this before)
'note strain' is the wordplay.
'note' becomes 'mi' (as in 'do re mi').
'strain' becomes 'stress' (synonyms).
'mi'+'stress'='MISTRESS'
'for' is the link.
(Other definitions for mistress that I've seen before include "Lady" , "Quickly, maybe" , "Husband's paramour" , "Fancy woman" , "Female teacher" .)