The definition of dissonant is things that don't go well together or things that are not harmonious.(adjective)
The sound that occurs when you play two cords on the piano that don't sound good together is an example of something that would be described as dissonant.
See dissonant in Webster's New World College Dictionary
See dissonant in American Heritage Dictionary 4
Origin: Middle English dissonaunt
Origin: , from Old French dissonant
Origin: , from Latin dissonāns, dissonant-
Origin: , present participle of dissonāre, to be dissonant
Origin: : dis-, apart; see dis-
Origin: + sonāre, to sound; see swen- in Indo-European roots.
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