From Longman Dictionary of Contemporary Englishmezzo-sopranoˌmezzo-soˈprano (also mezzo) noun [countable] APMa female singing voice that is lower than a soprano but higher than an alto, or a woman with a voice like this
Examples from the Corpus
mezzo-soprano• Parts are notated for him in five different clefs bass, tenor, alto, mezzo-soprano and soprano.• Yet the beneficent mezzo-soprano voice is not really the ideal instrument, and this soprano has a younger, fresher tone.• The late mezzo-soprano Jan DeGaetani makes a guest appearance in these 1973 sessions.• Anne Sofie von Otter, mezzo-soprano.• The voice had a curious quality, husky and high-pitched as if uncertain whether it was a light tenor or a throaty mezzo-soprano. 