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early 15c., from Middle French calamite (14c.), from Latin calamitatem (nominative calamitas) "damage, loss, failure; disaster, misfortune, adversity," origin obscure. Early etymologists associated it with calamus "straw" (see shawm); but it is perhaps from a lost root preserved in incolumis "uninjured," from PIE *kle-mo-, from base *kel- "to strike, cut" (see hilt).