Source : Webster's Revised Unabridged Dictionary (1913)

Inevitability \In*ev`i*ta*bil"i*ty\, n. [Cf. F.
   in['e]vitabilit['e].]
   Impossibility to be avoided or shunned; inevitableness.
   --Shelford.

Source : WordNet®

inevitability
     n : the quality of being unavoidable [syn: {inevitableness}]