Shack
late 19th century: perhaps from Mexican jacal, Nahuatl xacatli ‘wooden hut’. The early sense of the verb was ‘live in a shack’ (originally a US usage).
wiktionary
Origin unknown. Some authorities derive this word from Mexican Spanish jacal, from Nahuatl xacalli(“adobe hut”). [1]
Alternatively, the word may instead come from ramshackle/ ramshackly (e.g., old ramshackly house) or perhaps it may be a back-formation from shackly. [2]
Obsolete variant of shake. Compare Scots shag(“refuse of barley or oats”).
etymonline
shack (n.)
1878, American English and Canadian English, of unknown origin, perhaps from Mexican Spanish jacal, from Nahuatl (Aztecan) xacalli "wooden hut." Or perhaps 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.
Slang meaning "house" 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). As a verb, 1891 in the U.S. West in reference to men who "hole up" for the winter; from 1927 as "to put up for the night;" phrase shack up "cohabit" first recorded 1935 (in Zora Neale Hurston).
