the.com/clash

means To collide or conflict sharply — whether it's armies fighting, colors clashing on a shelf, or opinions grinding against each other.

from From Middle English 'clashen,' almost certainly imitative — a word invented to mimic the sound itself, like 'crash' and 'bash.' It first described the literal noise of metal striking metal (swords, cymbals, shields), then widened over the centuries to cover any sharp collision, sound-based or not — colors clashing, schedules clashing, armies clashing. The word still carries its onomatopoeic ring, which is why it feels so satisfying to say.