Wordnet 3.0
NOUN (1)
1. 
 a short and simple sonata; 
The Collaborative International Dictionary of English v.0.48:
Sonatina \So`na*ti"na\, n. [It.] (Mus.)
   A short and simple sonata.
   [1913 Webster] Soncy
WordNet (r) 3.0 (2006):
sonatina
    n 1: a short and simple sonata