Inevitability :: Inevitability (n.) Impossibility to be avoided or shunned; inevitableness.
Inevitable :: Inevitable (a.) Not evitable; incapable of being shunned; unavoidable; certain.
Inevitableness :: Inevitableness (n.) The state of being unavoidable; certainty to happen.
Inevitably :: Inevitably (adv.) Without possibility of escape or evasion; unavoidably; certainly.