Gathers in spare jumble (5)
I believe the answer is:
reaps
'gathers' is the definition.
(reaping is a kind of gathering)
'spare jumble' is the wordplay.
'jumble' is an anagram indicator.
'spare' with letters rearranged gives 'REAPS'.
'in' is the link.
(Other definitions for reaps that I've seen before include "Cuts, gathers grain" , "Harvests with strange spear" , "Harvests (a crop)" , "Gleans or harvests" , "crops" .)