Surplus pears are used (5)
I believe the answer is:
spare
'surplus' is the definition.
(I know that surplus can be written as spare)
'pears are used' is the wordplay.
'are used' indicates an anagram.
'pears' is an anagram of 'SPARE'.
(Other definitions for spare that I've seen before include "In reserve; pardon" , "Not required" , "Extra item just in case" , "Surplus to requirements" , "Thin; surplus" .)