The Collaborative International Dictionary of English v.0.48:

Toccata \Toc*ca"ta\, n. [It., fr. toccare to touch. See
   Touch.] (Mus.)
   An old form of piece for the organ or harpsichord, somewhat
   in the free and brilliant style of the prelude, fantasia, or
   capriccio.
   [1913 Webster] Toccatella

WordNet (r) 3.0 (2006):

toccata
    n 1: a baroque musical composition (usually for a keyboard
         instrument) with full chords and rapid elaborate runs in a
         rhythmically free style