Use spare fruit (5)
I believe the answer is:
pears
'fruit' is the definition.
(I've seen this before)
'use spare' is the wordplay.
'use' indicates anagramming the letters.
'spare' anagrammed gives 'PEARS'.
(Other definitions for pears that I've seen before include "Fruit trees" , "Fruit - singer with ..." , "Juicy fruits - spare them" , "Sweet juicy fruits" .)