Plant used to make brush? (5)
I believe the answer is:
shrub
'plant' is the definition.
(type of plant)
'to make brush?' is the wordplay.
'to make' indicates anagramming the letters.
'brush' with letters rearranged gives 'SHRUB'.
'used' acts as a link.
(Other definitions for shrub that I've seen before include "Perhaps Heather" , "Elder" , "Hazel perhaps" , "Brush? (anagr.)" , "Cordial" .)