The Collaborative International Dictionary of English v.0.48:

Verve \Verve\, n. [F.]
   Excitement of imagination such as animates a poet, artist, or
   musician, in composing or performing; rapture; enthusiasm;
   spirit; energy.
   [1913 Webster]

WordNet (r) 3.0 (2006):

verve
    n 1: an energetic style [syn: vitality, verve]