Make certain to head off criticism (6)
I believe the answer is:
ensure
'make certain' is the definition.
(synonyms)
'head off criticism' is the wordplay.
'head off' means to remove the first letter.
'criticism' becomes 'censure' (I've seen this before).
'censure' with its initial letter removed is 'ENSURE'.
'to' is the link.
(Other definitions for ensure that I've seen before include "See run (anag)" , "Make certain (something will occur)" , "Make certain for the future" , "warrant" , "Make certain that (something occurs)" .)