Deny brute is wrong (5)
I believe the answer is:
rebut
'deny' is the definition.
(thesaurus)
'brute is wrong' is the wordplay.
'is wrong' indicates anagramming the letters.
'brute' anagrammed gives 'REBUT'.
(Other definitions for rebut that I've seen before include "Drive back" , "Disprove an accusation" , "Refure or disprove" , "Contradict or disprove" , "Check" .)