New remit for hat (5)
I believe the answer is:
mitre
'hat' is the definition.
(I know that mitre is a type of hat)
'new remit' is the wordplay.
'new' indicates an anagram.
'remit' is an anagram of 'MITRE'.
'for' acts as a link.
(Other definitions for mitre that I've seen before include "symbol of ecclesiastical authority" , "See boss gear up" , "Corner joint - bishop's hat" , "Remit (anag.)" , "A bishop wears it" .)