Philosophically speaking, usually "not" is inevitable.
More inevitable, most inevitable
"It was inevitable that that would happen", "his death was inevitable", "losing that match was inevitable"...
more inevitable, most inevitable
With our score so high, I think that victory is inevitable. Making mistakes is inevitable for human beings.
Are factions inevitable?
death is inevitable
Death is inevitable.
"The consequences were inevitable."
is inevitable to go to the movies...
The opposite of inevitable can be avoidable, or escapable.
It is inevitable that you will die.
No, "inevitable" is an adjective, not a verb. It describes something that is certain to happen and cannot be avoided.