"very roughly built house or cabin," 1878, American English and Canadian English, originally in reference to temporary dwellings made by homesteaders while securing a claim, a word of unknown origin. Perhaps it is from Mexican Spanish jacal (from Nahuatl (Aztecan) xacalli "wooden hut"). Or perhaps it is a back-formation from dialectal English shackly "shaky, rickety" (1843), a derivative of shack, a dialectal variant of shake (v.). Another theory derives shack from ramshackle.
Yet another derives it from the verb shack meaning "to hibernate," as a bear or other animal, which is also a variant of shake (v.) in the sense of "be shed or fall," used of grain fallen from the ear and available for food for hogs, etc. (1520s); hence "the act or right of sending pigs or poultry out to 'run shack' after a harvest." Also compare shake-down "impromptu bed made upon loose straw" (1730).
The slang meaning "house" is attested by 1910. In early radio enthusiast slang, it was the word for a room or office set aside for wireless use, 1919, perhaps from earlier U.S. Navy use (1917).
The perhaps-related verb in the "hibernate" sense by 1891 in the U.S. West was used in reference to men who "hole up" for the winter; it is attested from 1927 as "to put up for the night;" the phrase shack up "cohabit" is recorded by 1935 (Zora Neale Hurston).
updated on July 24, 2022