Standard spare part (3)
I believe the answer is:
par
'standard' is the definition.
(standard of play in golf)
'spare part' is the wordplay.
'part' says the answer is hidden in the clue.
'PAR' can be found hidden inside 'spare'.
(Other definitions for par that I've seen before include "A number of golfing" , "Standard score for golfers" , "Regular score" , "Average standard" , "Normal level or standard" .)