c. 1200, "the universe, the world" (but not popular until 1848, when it was taken as the English equivalent to Humboldt's Kosmos in translations from German), from Latinized form of Greek kosmos "order, good order, orderly arrangement," a word with several main senses rooted in those notions: The verb kosmein meant generally "to dispose, prepare," but especially "to order and arrange (troops for battle), to set (an army) in array;" also "to establish (a government or regime);" "to deck, adorn, equip, dress" (especially of women). Thus kosmos had an important secondary sense of "ornaments of a woman's dress, decoration" (compare kosmokomes "dressing the hair," and cosmetic) as well as "the universe, the world."

Pythagoras is said to have been the first to apply this word to "the universe," perhaps originally meaning "the starry firmament," but it later was extended to the whole physical world, including the earth. For specific reference to "the world of people," the classical phrase was he oikoumene (ge) "the inhabited (earth)." Septuagint uses both kosmos and oikoumene. Kosmos also was used in Christian religious writing with a sense of "worldly life, this world (as opposed to the afterlife)," but the more frequent word for this was aiōn, literally "lifetime, age."

The word cosmos often suggested especially "the universe as an embodiment of order and harmony."

1726, "morbid longing to return to one's home or native country, severe homesickness considered as a disease," Modern Latin, coined 1688 in a dissertation on the topic at the University of Basel by scholar Johannes Hofer (1669-1752) as a rendering of German heimweh "homesickness" (for which see home + woe).

From Greek algos "pain, grief, distress" (see -algia) + nostos "homecoming," from neomai "to reach some place, escape, return, get home," from PIE *nes- "to return safely home" (cognate with Old Norse nest "food for a journey," Sanskrit nasate "approaches, joins," German genesen "to recover," Gothic ganisan "to heal," Old English genesen "to recover"). French nostalgie is in French army medical manuals by 1754.

Originally in reference to the Swiss and said to be peculiar to them and often fatal, whether by its own action or in combination with wounds or disease.

[Dr. Scheuzer] had said that the air enclosed in the bodies of his countrymen, being in Æquilibrium with a rare and light air that surrounds them, was overloaded in lower countries with an air more dense and heavier, which compressing and obstructing the capillary vessels, makes the circulation slow and difficult, and occasions many sad symptoms. [Account of the publication of "Areographia Helvetiæ" in New Memoirs of Literature, London, March 1726] 

By 1830s the word was used of any intense homesickness: that of sailors, convicts, African slaves. "The bagpipes produced the same effects sometimes in the Scotch regiments while serving abroad" [Penny Magazine," Nov. 14, 1840]. It is listed among the "endemic diseases" in the "Cyclopaedia of Practical Medicine" [London, 1833, edited by three M.D.s], which defines it as "The concourse of depressing symptoms which sometimes arise in persons who are absent from their native country, when they are seized with a longing desire of returning to their home and friends and the scenes their youth ...."

It was a military medical diagnosis principally, and was considered a serious medical problem by the North in the American Civil War:

In the first two years of the war, there were reported 2588 cases of nostalgia, and 13 deaths from this cause. These numbers scarcely express the real extent to which nostalgia influenced the sickness and mortality of the army. To the depressing influence of home-sickness must be attributed the fatal result in many cases which might otherwise have terminated favorably. ["Sanitary Memoirs of the War," U.S. Sanitary Commission, N.Y.: 1867]

Transferred sense (the main modern one) of "wistful yearning for the past" is recorded by 1920, perhaps from such use of nostalgie in French literature. The longing for a distant place also necessarily involves a separation in time.

Middle English pigge "a young pig" (mid-13c., late 12c. as a surname), probably from Old English *picg, found in compounds, but, like dog, its further etymology unknown. The older general word for adults was swine, if female, sow, if male, boar. Apparently related to Low German bigge, Dutch big ("but the phonology is difficult" -- OED).

By early 14c. pig was used of a swine or hog regardless of age or sex. Applied to persons, usually in contempt, since 1540s; the derogatory meaning "police officer" has been in underworld slang at least since 1811.

The pigs frisked my panney, and nailed my screws; the officers searched my house, and seized my picklock keys. ["Dictionary of Buckish Slang, University Wit and Pickpocket Eloquence," London, 1811]

Another Old English word for the animal was fearh, which is related to furh "furrow," from PIE *perk- "dig, furrow" (source also of Latin porcus "pig," see pork). "This reflects a widespread IE tendency to name animals from typical attributes or activities" [Lass].

Synonyms grunter, porker are from sailors' and fishermen's euphemistic avoidance of uttering the word pig at sea, a superstition perhaps based on the fate of the Gadarene swine, who drowned. The image of a pig in a poke is attested from late 14c. (see poke (n.1)). Flying pigs as a type of something unreal is from 1610s.

1540s, originally "person hired to remove refuse from streets," a modification of Middle English scavager, scawageour (late 14c.), the title of a London official who originally was charged with collecting tax on goods sold by foreign merchants.

This is from Middle English scavage, scauage (Anglo-French scawage) "toll or duty exacted by a local official on goods offered for sale in one's precinct" (c. 1400), from Old North French escauwage "inspection," from a Germanic source (compare Old High German scouwon, Old English sceawian "to look at, inspect;" see show (v.)).

The scavenger later was charged with inspection and maintenance of streets: Blount's description ("Glossographia," 1656) is "an Officer well known in London, that makes clean the streets, by scraping up and carrying away the dust and durt." The modern general sense of the word "one who collects and consumes or puts to use what has been discarded" evolved through the notion of "collect and dispose of rubbish."

The word came to be regarded as an agent noun in -er, but the verb scavenge (q.v.) is a late back-formation from the noun. For the unetymological -n- (c. 1500), compare harbinger, passenger, messenger, etc. Extended 1590s to animals that feed on decaying matter. Scavenger hunt is attested from 1937. Mayhew (1851) has scavagery "street-cleaning, removal of filth from streets."

1859, thieves' slang, "counterfeit, sham, bad, spurious," a word of unknown origin. Century Dictionary suggests it is a dialectal variant of snithe, itself a dialectal adjective meaning "sharp, cutting," used of the wind, from the Middle English verb snithen "to cut," from Old English snithan, which is cognate with German schneiden.

In earliest use it seems to have been most commonly applied to counterfeit coin. Farmer and Henley ("Slang and Its Analogues," 1903) has it as "bad, wretched, contemptible, or (army) dirty." Of persons, "characterized by low cunning and sharp practice," by 1874 (Hotten). Sense of "sneering" is attested by 1928, perhaps via the earlier noun sense of "hypocrisy, malicious gossip" (1902). Related: Snidely; snideness.

The tradition that a first-rate man is less a first-rate man if, encountering a snide detraction of himself that has no respect for the facts, he makes a critical riposte, strikes me as being just about as silly as anything I have run across during many years spent in this silly world. I speak, of course and obviously enough, not of snide criticism written by essentially snide men, but of the species of snide criticism that is every once in a while written by men who should know better. [George Jean Nathan, "Clinical Notes," The American Mercury, June 1928]

Old English stæf (plural stafas), "walking stick, strong pole used for carrying, rod used as a weapon, pastoral staff," probably originally *stæb, from Proto-Germanic *stab- (source also of Old Saxon staf, Old Norse stafr, Danish stav, Old Frisian stef, Middle Low German and Middle Dutch staf, Old High German stab, German Stab, Gothic *stafs "element;" Middle Dutch stapel "pillar, foundation").

This is reconstructed to be from PIE root *stebh- "post, stem, to support, place firmly on, fasten" (source also of Old Lithuanian stabas "idol," Lithuanian stiebas "staff, pillar;" Old Church Slavonic stoboru "pillar;" Sanskrit stabhnati "supports;" Greek stephein "to tie around, encircle, wreathe," staphyle "grapevine, bunch of grapes;" Old English stapol "post, pillar").

As "pole from which a flag is flown," 1610s. In musical notation from 1660s. Sense of "group of military officers that assists a commander" is attested from 1702, apparently from German, from the notion of the baton that is a badge of office or authority (a sense attested in English from 1530s); hence staff officer (1702), staff-sergeant (1811). The meaning "group of employees (as at an office or hospital)" is attested by 1837.

Staff of life "bread" is from the Biblical phrase break the staff of bread meaning "cut off the supply of food" (Leviticus xxvi.26), translating Hebrew matteh lekhem.

The Old English word, in plural, was the common one used for "letter of the alphabet, character," hence "writing, literature," and many compounds having to do with writing, such as stæfcræft "grammar," stæfcræftig "lettered," stæflic "literary," stæfleahtor "grammatical error," with leahtor "vice, sin, offense."

c. 1200, "animal hide" (usually dressed and tanned), from Old Norse skinn "animal hide, fur," from Proto-Germanic *skinth- (source also of rare Old English scinn, Old High German scinten, German schinden "to flay, skin;" German dialectal schind "skin of a fruit," Flemish schinde "bark"), from PIE *sken- "to peel off, flay" (source also of Breton scant "scale of a fish," Irish scainim "I tear, I burst"), extended form of root *sek- "to cut."

The usual Anglo-Saxon word is hide (n.1). The meaning "epidermis of a living animal or person" is attested from early 14c.; extended to fruits, vegetables, etc. late 14c. Jazz slang sense of "drum" is from 1927. As short for skinhead from 1970. As an adjective, it formerly had a slang sense of "cheating" (1868, compare the verb); that of "pornographic" is attested from 1968. Skin deep "superficial, not deeper than the thickness of the skin" (also literally, of wounds, etc.) is attested by 1610s:

All the carnall beauty of my wife, Is but skin-deep.

[Sir Thomas Overbury, "A Wife," 1613; the poem was a main motive for his murder]

The skin of one's teeth as the narrowest of margins is attested from 1550s in the Geneva Bible, a literal translation of the Hebrew text in Job xix.20. To get under (someone's) skin "annoy" is from 1896. Skin graft is from 1871. Skin merchant "recruiting officer" is from 1792 (the older sense is "dealer in hides"). Skin and bone as a description of emaciation or extreme leanness is in Middle English:

Ful of fleissche Y was to fele, Now ... Me is lefte But skyn & boon. [hymn, c. 1430]

mid-14c., relien, "to gather, assemble" an army, followers, a host, etc. (transitive and intransitive), from Old French relier "assemble, put together; fasten, fasten again, attach, rally, oblige," from Latin religare "fasten, bind fast," from re-, here perhaps an intensive prefix (see re-), + ligare "to bind" (from PIE root *leig- "to tie, bind").

The older sense now are obsolete. The meaning "depend on with full trust and confidence, attach one's faith to" a person or thing is from 1570s, perhaps via the notion of "rally to, fall back on." Typically used with on, perhaps by influence of unrelated lie (v.2) "rest horizontally." Related: Relied; relying.

The verb rely, in the orig. sense 'fasten, fix, attach,' came to be used with a special reference to attaching one's faith or oneself to a person or thing (cf. 'to pin one's faith to a thing,' 'a man to tie to,' colloquial phrases containing the same figure); in this use it became, by omission of the object, in transitive, and, losing thus its etymological associations (the other use, 'bring together again, rally,' having also become obsolete), was sometimes regarded, and has been by some etymologists actually explained, as a barbarous compound of re- + E. lie (1) rest, .... But the pret. would then have been *relay, pp. *relain. [Century Dictionary]