Contralto \Con*tral"to\ (? or ?), a. (Mus.) Of or pertaining to a contralto, or to the part in music called contralto; as, a contralto voice.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Contralto \Con*tral"to\ (? or ?), n. [It., fr. contra + alto. See Alto.]

(Mus.)
   (a) The part sung by the highest male or lowest female voices; the alto or counter tenor.
   (b) the voice or singer performing this part; as, her voice is a contralto; she is a contralto.

Note: The usual range of the contralto voice is from G, below middle C, to the C above that; though exceptionally it embraces two octaves.

Source: Webster's Revised Unabridged Dictionary (1913)