Consents to use grease? (6)
I believe the answer is:
agrees
'consents to' is the definition.
(agreeing is a kind of consenting to)
'use grease?' is the wordplay.
'use' indicates anagramming the letters.
'grease' is an anagram of 'AGREES'.
(Other definitions for agrees that I've seen before include "Is of one mind" , "is in accord" , "Accedes or concurs" , "Shakes hands" , "Grease (anag.)" .)