The Collaborative International Dictionary of English v.0.48:

Cantabile \Can*ta"bi*le\, a. [It., cantare to sing.] (Mus.)
   In a melodious, flowing style; in a singing style, as opposed
   to bravura, recitativo, or parlando.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Cantabile \Can*ta"bi*le\, n. (Mus.)
   A piece or passage, whether vocal or instrumental, peculiarly
   adapted to singing; -- sometimes called cantilena.
   [1913 Webster]

WordNet (r) 3.0 (2006):

cantabile
    adj 1: smooth and flowing [syn: cantabile, singing]