Fondness for a swan-song (8)
I believe the answer is:
penchant
'fondness' is the definition.
(thesaurus)
'a swan-song' is the wordplay.
'a swan' becomes 'pen' (pen is a kind of swan).
'song' becomes 'chant' (I've seen this before).
'pen'+'chant'='PENCHANT'
'for' acts as a link.
(Other definitions for penchant that I've seen before include "Inclination, bent" , "Disposition" , "Predilection, preference" , "Inclination; taste" , "'Predilection, a strong liking (8)'" .)