Search Result for "castrato": 
Wordnet 3.0

NOUN (1)

1. a male singer who was castrated before puberty and retains a soprano or alto voice; 



The Collaborative International Dictionary of English v.0.48:

Castrato \Cas*tra"to\, n. [L., properly p. p. of castrare. See
   Castrate.]
   A male person castrated for the purpose of improving his
   voice for singing; an artificial, or male, soprano. --Swift.
   [1913 Webster]


WordNet (r) 3.0 (2006):

castrato
    n 1: a male singer who was castrated before puberty and retains
         a soprano or alto voice