The Collaborative International Dictionary of English v.0.48:
Mezzo \Mez"zo\, a. [It., from L. medius middle, half. See Mid, a.] (Mus.) Mean; not extreme. [1913 Webster]WordNet (r) 3.0 (2006):
mezzo n 1: a soprano with a voice between soprano and contralto [syn: mezzo-soprano, mezzo] 2: the female singing voice between contralto and soprano [syn: mezzo-soprano, mezzo]