Simple past tense and past participle of clash.(verb)
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Use "clashed" in a sentence
"True, Wallace and Palin clashed on the campaign trail, and Palin's book last year singled out Wallace for criticism."
"But once again, Einstein clashed with some of the donors and their choices for administrators."
"The heap of gold became as turbulent as the water of a cascade, and leaped and sang; the millions of little sonorous coins clashed against each other, and then all was silent and they vanished."