breakdown (n.)

also break-down, 1832, "a collapse, a falling apart," from the verbal phrase (attested by late 14c. in the sense "take down by breaking" (trans.); 1831 in the intransitive sense "come down by breaking; 1856 as "to fail through incapacity, excess emotion, etc."); see break (v.) + down (adv.). The noun, specifically of machinery, is from 1838; meaning "an analysis in detail" is from 1936 (from the verbal phrase in the sense "analyze, classify," 1934). Also in 19c. American English "a noisy, lively dance sometimes accompanied by singing" (1864). Nervous breakdown is from 1866.