![](http://image.absoluteastronomy.com/images//topicimages/u/un/unison.gif)
UNISON
WordNet
noun
(1) (music) two or more sounds or tones at the same pitch or in octaves
"Singing in unison"
(2) Occurring together or simultaneously
"The two spoke in unison"
(3) Corresponding exactly
"Marching in unison"
WiktionaryText