[ yoo-nuh-suh n, -zuh n ]
/ ˈyu nə sən, -zən /


coincidence in pitch of two or more musical tones, voices, etc.
the musical interval of a perfect prime.
the performance of musical parts at the same pitch or at the octave.
a sounding together in octaves, especially of male and female voices or of higher and lower instruments of the same class.
a process in which all elements behave in the same way at the same time; simultaneous or synchronous parallel action: to march in unison.


    in unison, in perfect accord; corresponding exactly: My feelings on the subject are in unison with yours.

Origin of unison

1565–75; < Medieval Latin ūnisonus of a single sound, equivalent to Latin ūni- uni- + sonus sound
Related formsnon·u·ni·son, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for unison

British Dictionary definitions for unison (1 of 2)


/ (ˈjuːnɪsən, -zən) /


  1. the interval between two sounds of identical pitch
  2. (modifier) played or sung at the same pitchunison singing
complete agreement; harmony (esp in the phrase in unison)
Derived Formsunisonous, unisonal or unisonant, adjective

Word Origin for unison

C16: from Late Latin ūnisonus, from uni- + sonus sound

British Dictionary definitions for unison (2 of 2)


/ (ˈjuːnɪsən) /


(in Britain) a trade union representing local government, health care, and other workers: formed in 1993 by the amalgamation of COHSE, NALGO, and NUPE
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for unison



1570s, from Middle French unisson "unison, accord of sound" (16c.), from Medieval Latin unisonus "having one sound, sounding the same," from Late Latin unisonius "in immediate sequence in the scale, monotonous," from Latin uni- "one" (see one) + sonus "sound" (see sound (n.1)). Sense of "harmonious agreement" is first attested 1640s.

Online Etymology Dictionary, © 2010 Douglas Harper

Culture definitions for unison


Playing or singing the same musical notes, or notes separated from each other by one or several octaves. Musicians who perform in unison are not playing or singing chords.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.