shake-down n.

Middle English shaken, from Old English sceacan "move (something) quickly to and fro, cause to move with quick vibrations; brandish; move the body or a part of it rapidly back and forth;" also "go, glide, hasten, flee, depart" (as in sceacdom "flight"); also intransitive, of persons or parts of the body, "to tremble" especially from fever, cold, fear (class VI strong verb; past tense scoc, past participle scacen).

This is reconstructed to be from Proto-Germanic *skakanan "to shake, swing," also "to escape" (source also of Old Norse, Swedish skaka, Danish skage "to shift, turn, veer"). There are said to be no certain cognates outside Germanic, but some sources suggest a PIE root *(s)keg- "to jump, to move" (compare Sanskrit khaj "to agitate, churn, stir about," Old Church Slavonic skoku "a leap, bound," Welsh ysgogi "move"). Also compare shock (n.1).

Of the ground in earthquakes, c. 1300. The meaning "seize and shake" (someone or something else) is from early 14c. From late 14c. in reference to mixing ingredients, etc., by shaking a container. The meaning "weaken, impair" in any respect is from late 14c. on the notion of "make unstable." The meaning "rid oneself of by abrupt twists" is from c. 1200; the modern colloquial use for "get rid of, cast off, abandon" (by 1872, American English) is likely a new extension on the notion of "throw off by a jolting or abrupt action," perhaps with horses in mind. The verb also was used in Middle English as "evade" responsibility, etc.

To shake hands "greet or salute by grasping one another's hands" dates from 1530s. Colloquial shake a (loose) leg "hurry up" is recorded by 1904; to shake a heel (sometimes foot) is an old or provincial way to say "dance" (1660s); to shake (one's) elbow (1620s) meant "to gamble at dice." In 16c.-18c. English, shake (one's) ears was "bestir oneself," an image of animal awakenings. The phrase more _____ than you can shake a stick at "more than you can count" is attested from 1818 (Lancaster, Pa., "Journal"), American English. To shake (one's) head "move one's head from side to side as a sign of disapproval" is recorded from c. 1300.

"in a descending direction, from a higher to a lower place, degree, or condition," late Old English shortened form of Old English ofdune "downwards," originally of dune "off from (the) hill," from dune "from the hill," dative of dun "hill" (see down (n.2)). The "hill" word is general in Germanic, but this sense development is peculiar to English. As a preposition, "in a descending direction upon or along,"  from late 14c.

To be down on "express disapproval of" is by 1851. Down home is from 1828 as "in one's home region," as an adjective phrase meaning "unpretentious" by 1931, American English. Down the hatch as a toast is from 1931. Down to the wire is 1901, from horse-racing.

Down Under "Australia and New Zealand" attested from 1886; Down East "Maine" is from 1825; Down South "in the Southern states of the U.S." is attested by 1834. Down the road "in the future" is by 1964, U.S. colloquial. Down-to-earth "everyday, ordinary, realistic" is by 1932.

"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).