unison
uni.son \'yu:-n*-s*n, -n*-z*n\ n [MF, fr. ML unisonus having the same sound, fr. L uni- + sonusX sound - more at SOUND 1a: identity in musical pitch; specif : the interval of a perfect p rime 1b: the state of being so tuned or sounded 1c: the writing, playing, or singing of parts in a musical passage at the s ame pitch or in octaves 2: a harmonious agreement or union : CONCORD - unison aj