A shine's possibly required for a boot (7)
I believe the answer is:
hessian
'boot' is the definition.
(type of boot)
'a shine's possibly' is the wordplay.
'possibly' is an anagram indicator.
'a'+'shines'='ashines'
'ashines' is an anagram of 'HESSIAN'.
'required for a' acts as a link.
(Other definitions for hessian that I've seen before include "Hemp, jute fabric" , "Cloth made from jute" , "It's rather like sacking" , "Coarse fabric used in sacks" , "Jute clothing" .)