also clampdown, 1940 in the figurative sense "a firm, oppressive or harsh suppression or preventive action," from verbal phrase clamp down "use pressure to keep down" (1924). The verbal phrase in the figurative sense is recorded from 1941. See clamp (v.) + down (adv.).

"that is done or which involves sitting down," 1836 in reference to meals; 1936 in reference to strikes where the workplace is occupied; from the verbal phrase meaning "take a seat, seat oneself" (c. 1200), from sit (v.) + down (adv.). Sit down (v.) meaning "put up (with)" is attested from c. 1600, hence to (not) take something sitting down. As a noun, sit-down "act of sitting down" is from 1861, especially a sitting down together for friendly or social intercourse.

also shakedown, 1730, "impromptu bed made upon loose straw," from the verbal phrase; see shake (v.) + down (adv.). The verbal phrase shake down is attested from late 14c. as "shake into place, compact by shaking" also "cause to totter and fall." The meaning "forced contribution" (1902) is from the verbal phrase in a slang sense of "blackmail, extort" (1872). Meaning "a thorough search" is from 1914; perhaps from the notion of measuring corn; the verbal sense of "to frisk or search" is by 1915 in police reporting.

"reduction in price," 1880, from the verbal expression mark down "reduce in price" (1859), from mark (v.) in the sense of "put a numerical price on an object for sale" + down (adv.). Mark down as "make a note of" is by 1881.

"insult, snub," 1962, from verbal phrase put down "to snub," attested from c. 1400 in this sense, earlier (c. 1300) "to lower, let down," also (mid-14c.) "to throw down, reject;" see put (v.) + down (adv.). To put (something) down "end by force or authority" (a rebellion, etc.) is from mid-14c.  Compare set-down "a rebuff, a scolding" (1780).

"setback, sudden change for the worse in one's circumstances," 1840, from verbal phrase; see come (v.) + down (adv.). In 16c.-17c. "total destruction" was expressed metaphorically as "to come to Castle Comedown" (1560s).

also letdown, "a disappointment," 1768, from let (v.) + down (adv.). The verbal phrase is from mid-12c. in a literal sense "cause to be lowered," of drawbridges, etc.; figuratively by 1754.

also rub-down, "an act of rubbing down," by 1885, from verbal phrase, from rub (v.) + down (adv.).

1866, of persons, "to have the health or strength reduced," from the verbal phrase; see run (v.) + down (adv.). From 1896 of places, "dilapidated, shabby, seedy;" by 1894 of clocks, etc., "completely unwound." The earliest sense is "oppressed" (1680s). Compare rundown (n.).

The verbal phrase run down as "have the motive power exhausted" (of clocks, etc.) is by 1761; of persons, etc., "become weak or exhausted," by 1828. To run (something or someone) down "disparage, abuse" is by 1660s. 

also knockdown, 1680s, from the verbal phrase knock down, attested from mid-15c. in the sense "fell to the ground;" see knock (v.) + down (adv.). As a noun from 1809. Phrase knock-down, drag-out is from 1827.