The Collaborative International Dictionary of English v.0.48:

Vitality \Vi*tal"i*ty\ (?; 277), n. [L. vitalitas: cf. F.
   vitalit['e].]
   The quality or state of being vital; the principle of life;
   vital force; animation; as, the vitality of eggs or vegetable
   seeds; the vitality of an enterprise.
   [1913 Webster]

WordNet (r) 3.0 (2006):

vitality
    n 1: an energetic style [syn: vitality, verve]
    2: a healthy capacity for vigorous activity; "jogging works off
       my excess energy"; "he seemed full of vim and vigor" [syn:
       energy, vim, vitality]
    3: (biology) a hypothetical force (not physical or chemical)
       once thought by Henri Bergson to cause the evolution and
       development of organisms [syn: life force, vital force,
       vitality, elan vital]
    4: the property of being able to survive and grow; "the vitality
       of a seed" [syn: animation, vitality]