shack
/ʃak/
noun
A roughly built hut or cabin.
verb
[no object]
shack up
informal
Move in or live with someone as a lover.
Origin
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).
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A tiny house is generally built with care and precision, though its size might make you think it is just a shack.