DuckCorp Dico

Found one definition

1.                 From WordNet (r) 3.0 (2006):
                   
   
   
                   
                     
   alto
       adj 1: of or being the lowest female voice [syn: alto,
              contralto]
       2: of or being the highest male voice; having a range above that
          of tenor [syn: countertenor, alto]
       3: (of a musical instrument) second highest member of a group;
          "alto clarinet or recorder"
       n 1: a singer whose voice lies in the alto clef
       2: the lowest female singing voice [syn: contralto, alto]
       3: the highest adult male singing voice [syn: countertenor,
          alto]
       4: (of a musical instrument) the second highest instrument in a
          family of musical instruments
       5: the pitch range of the lowest female voice