mez·za vo·ce I. \|metsə|vō(ˌ)chā, -edzə-\adverb (or adjective) Etymology: Italian, literally, half voice : with medium or half volume of tone — used as a direction in music II. noun : a medium or half volume of tone < the quality of her voice in mezza voce was warm and expressive — Winthrop Sargeant >