Sweetheart is trying to retain style (8)
I believe the answer is:
artistry
'style' is the definition.
(thesaurus)
'sweetheart is trying to retain' is the wordplay.
'to retain' indicates the answer is hidden within the clue (I've seen 'retains' mean this).
'ARTISTRY' is hidden in the letters of 'sweetheart is trying'.
(Other definitions for artistry that I've seen before include "Creativity" , "poetic skill" , "Virtuosity - craftsmanship" , "Superior skill" , "Skilled workmanship" .)