Inevitable, all right (4)
I believe the answer is:
sure
I believe this is a double definition.
'inevitable' is the first definition.
(similar in meaning)
'all right' is the second definition.
(thesaurus)
(Other definitions for sure that I've seen before include "See 12" , "Completely confident that one is right" , "Feeling no doubt" , "Confident sort of ruse" , "Agreed" .)