clash 
(klăsh)
(klăsh)v. clashed, clash·ing, clash·es
v.intr.
1. To collide with a loud, harsh, usually metallic noise: cymbals clashing.
2.
a. To meet in violent conflict: armies that clashed on the plain.
b. To be in opposition or disagreement: an eyewitness account that clashed with published reports.
3. To create an unpleasant visual impression when placed together: colors that clash.
v.tr.
To strike together with a loud, harsh, metallic noise.
n.
1. A loud, harsh noise, such as that made by two metal objects in collision.
2.
a. A violent conflict or confrontation.
b. A disagreement or state of opposition: a clash of political ideologies. See Synonyms at conflict.
3. An incongruity or unpleasant juxtaposition of different colors or elements.
[Imitative.]