CID react criminally to authorise (8)
I believe the answer is:
accredit
'authorise' is the definition.
(I've seen this in another clue)
'cid react criminally' is the wordplay.
'criminally' is an anagram indicator (I've seen this in other clues).
'cid'+'react'='cidreact'
'cidreact' anagrammed gives 'ACCREDIT'.
'to' is the link.
(Other definitions for accredit that I've seen before include "Certify, approve" , "Cat cried (anag.)" , "Give official recognition to" , "Accept as true" , "CID trace (anag.)" .)