Harsh and inharmonious in sound; discordant. (adjective)
Being at variance; disagreeing. (adjective)
Music Constituting or producing a dissonance. (adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "dissonant" in a sentence
"Not doing well results in dissonant silence or an intentionally dissonant interruption."
"This is a fairly transparent way of rejecting experimental music -- just as many others reject experimental fiction or poetry because it's also "dissonant" -- and Pitt does a good job of diagnosing its flaws."
"Thus, any music that doesn't manifest a recognizable emotion (by implication at least, all of "dissonant" modernist music) couldn't be music."