Unison
U'NISON, noun [Latin unus, one, and sonur, sound.]
1. In music, an accordance or coincidence of sounds, proceeding from an equality in the number of vibrations made in a given time by a sonorous body. If two chords of the same matter have equal length, thickness and tension, they are said to be in unison and their sounds will be in unison Sounds of very different qualities and force may be in unison; as the sound of a bell may be in unison with a sound of a flute. unison then consists in sameness of degree, or similarity in respect to gravity or acuteness, and is applicable to any sound, whether of instruments or of the human organs, etc.
2. A single unvaried note.
In unison in agreement; in harmony.
U'NISON, adjective Sounding alone.
Sounds intermix'd with voice, choral or unison