It may have been said in jest, but a legion of Hollywood actresses would have nodded ruefully in unison.
The call for a microphone check began with one person, but soon everyone was chanting in unison.
Below, the crowd chanted in unison, “The people demand the fall of the regime!”
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.