<p><strong>Noun</strong></p><ul><li>a discordant state; disagreement; discord</li><li>an instance of this</li><li>dissonance</li><li>Geology: lack of parallelism between adjacent strata, as in an angular unconformity</li><li>(in genetic studies) the degree of dissimilarity in a pair of twins with respect to the presence or absence of a disease or trait</li></ul>