Agree, bout fixed for sure (2,5)
I believe the answer is:
no doubt
'for sure' is the definition.
(I've seen this in another clue)
'agree bout fixed' is the wordplay.
'agree' becomes 'nod' (I've seen this before).
'fixed' is an anagram indicator.
'bout' anagrammed gives 'oubt'.
'nod'+'oubt'='NO DOUBT'
(Other definitions for no doubt that I've seen before include "sign of agreement" , "Bound to, unquestionably" , "Surely" , "Almost certainly" , "To be sure" .)