Many reluctant to take the stuff (5)
I believe the answer is:
cloth
'the stuff' is the definition.
(thesaurus)
'many reluctant' is the wordplay.
'many' becomes 'c' (C is the Roman numeral for 100).
'reluctant' becomes 'loth' ('loth' can be a synonym of 'reluctant').
'c'+'loth'='CLOTH'
'to take' acts as a link.
(Other definitions for cloth that I've seen before include "Fabric, textile" , "The clergy" , "Textiles" , "Woven material" , "ministers" .)