n. pl. al·tos
1. A low female singing voice; a contralto.
2. A countertenor.
a. The range between soprano and tenor.
b. A singer whose voice lies within this range.
c. An instrument that sounds within this range.
d. A vocal or instrumental part written in this range.
[Italian, from Latin altus, high; see al-2 in the Appendix of Indo-European roots.]
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