breakdown (n.)youdaoicibaDictYouDict[breakdown 词源字典]
"a collapse," 1832, from break (v.) + down (adv.). The verbal phrase is attested from late 14c. The noun, specifically of machinery, is from 1838; meaning "an analysis in detail" is from 1936. Nervous breakdown is from 1905.[breakdown etymology, breakdown origin, 英语词源]