Source : Webster's Revised Unabridged Dictionary (1913)

Viability \Vi`a*bil"i*ty\, n.
   The quality or state of being viable. Specifically:
   (a) (Law) The capacity of living after birth. --Bouvier.
   (b) The capacity of living, or being distributed, over wide
       geographical limits; as, the viability of a species.

Source : WordNet®

viability
     n 1: (of living things) capable of normal growth and development
     2: capable of become practical and useful