Old English burg, burh "a dwelling or dwellings within a fortified enclosure," from Proto-Germanic *burgs "hill fort, fortress" (source also of Old Frisian burich "castle, city," Old Norse borg "wall, castle," Old High German burg, buruc "fortified place, citadel," German Burg "castle," Gothic baurgs "city"), which Watkins derives from from PIE root *bhergh- (2) "high," with derivatives referring to hills, hill forts, and fortified elevations.

In German and Old Norse, chiefly as "fortress, castle;" in Gothic, "town, civic community." The meaning shifted in Old English from "fortress," to "fortified town," then simply "town" (16c., especially one possessing municipal organization or sending representatives to Parliament). In some U.S. states (originally Pennsylvania, 1718) often an incorporated town; in Alaska, however, it is the equivalent of a county. As "one of the five administrative divisions of New York City," it dates from the consolidation of 1898; in London, its use dates from the London Government Act of 1899.

The Scottish form is burgh. The Old English dative singular byrig survives in many place names as -bury.

mid-14c., slike, "smooth, glossy, sleek" (of skin or hair), probably from an unrecorded Old English word related to slick (v.). The sense of "smooth, plausible" is recorded from 1590s, deteriorating by 1807 into "clever in deception." That of "first-class, excellent" is from 1833. Related: Slickly; slickness.

Middle English toun, "inhabited place having some degree of local government," from Old English tun "enclosure, garden, field, yard; farm, manor; homestead, dwelling house, mansion;" later "group of houses, village, farm," from Proto-Germanic *tunaz, *tunan "fortified place" (source also of Old Saxon, Old Norse, Old Frisian tun "fence, hedge," Middle Dutch tuun "fence," Dutch tuin "garden," Old High German zun, German Zaun "fence, hedge").

This was an early Germanic borrowing from Celtic *dunon "hill, hill-fort" (source also of Old Irish dun, Welsh din "fortress, fortified place, camp," dinas "city," Gaulish-Latin -dunum in place names). It is reconstructed to be from PIE *dhu-no- "enclosed, fortified place, hill-fort," from root *dheue- "to close, finish, come full circle" (see down (n.2)).

The meaning "collection of houses larger than a village" (mid-12c.) arose after the Norman conquest from the use of this word to correspond to French ville. In medieval England the sense tended toward "large number of houses associated with a market." In U.S. it is often used in the meaning "township."

The modern word is partially a generic term, applicable to cities of great size as well as places intermediate between a city and a village; such use is unusual, the only parallel is perhaps Latin oppidium, which occasionally was applied even to Rome or Athens (each of which was more properly an urbs).

From Middle English, typically figurative of a place of sophistication. The game of town ball, an early version of baseball, is recorded by that name from 1852. A town car (1907) originally was a motor car with an enclosed passenger compartment and open driver's seat.

To be in town or out of town is from 14c. On the town (or upon the town) "living the high life, in the fashionable swing of things" is attested from 1712. Man about town "one constantly seen at public and private functions" is attested from 1734. Colloquial go to town "do (something) energetically" is recorded by 1933. 

Town-crier is attested from c. 1600; town-talk "common talk of a town, a subject of gossip" is by 1650s; town clock is by 1466 (in reference to Dublin).

"fortress commanding a city," 1580s, from French citadelle (15c.), from Italian cittadella, diminutive of Old Italian cittade "city" (Modern Italian citta), from Latin civitatem (nominative civitas; also source of Portuguese citadella, Spanish ciuadela; see city).

"having the manners, look, or style of city life," 1819, American English, from city + past participle ending of words in -fy. Compare older countrified.

c. 1300, citisein (fem. citeseine) "inhabitant of a city or town," from Anglo-French citesein, citezein "city-dweller, town-dweller, citizen" (Old French citeien, 12c., Modern French citoyen), from cite (see city) + -ain (see -ian). According to Middle English Compendium, the -s-/-z- in Anglo-French presumably replaced an earlier *-th-. Old English words were burhsittend and ceasterware.

Sense of "freeman or inhabitant of a country, member of the state or nation, not an alien" is late 14c. Meaning "private person" (as opposed to a civil officer or soldier) is from c. 1600. As a title, 1795, from French: During the French Revolution, citoyen was used as a republican alternative to Monsieur.

Citizen's arrest, one carried out by a private person, without a warrant, allowable in certain cases, is recorded from 1941; citizen's band (radio) from 1947. Citizen of the world (late 15c.) translates Latin civem totius mundi, Greek kosmopolites.

He is not a citizen who is not disposed to respect the laws and to obey the civil magistrate; and he is certainly not a good citizen who does not wish to promote, by every means in his power, the welfare of the whole society of his fellow-citizens. [Adam Smith, "Theory of Moral Sentiments"]

"a view of a city," 1856, from city + ending from landscape.

"city which is an independent sovereign state," 1877, from city + state (n.).

1540s, "pertaining to a city or citizenship," originally in civic crown (Latin corona civica), a chaplet of oak leaves awarded to one who saved the life of a fellow citizen in battle, from Latin civicus "of a citizen," adjectival derivative of civis "townsman" (see city). Sense of "having to do with citizens" is from 1790.

late 14c., "relating to civil law or life; pertaining to the internal affairs of a state," from Old French civil "civil, relating to civil law" (13c.) and directly from Latin civilis "relating to a society, pertaining to public life, relating to the civic order, befitting a citizen," hence by extension "popular, affable, courteous;" alternative adjectival derivative of civis "townsman" (see city).

Meaning "not barbarous, civilized" is from 1550s. Specifically "relating to the commonwealth as secularly organized" (as opposed to military or ecclesiastical) by 1610s. Meaning "relating to the citizen in his relation to the commonwealth or to fellow citizens" also is from 1610s.

The word civil has about twelve different meanings; it is applied to all manner of objects, which are perfectly disparate. As opposed to criminal, it means all law not criminal. As opposed to ecclesiastical, it means all law not ecclesiastical: as opposed to military, it means all law not military, and so on. [John Austin, "Lectures on Jurisprudence," 1873]

The sense of "polite" was in classical Latin, but English did not pick up this nuance of the word until late 16c., and it has tended to descend in meaning to "meeting minimum standards of courtesy." "Courteous is thus more commonly said of superiors, civil of inferiors, since it implies or suggests the possibility of incivility or rudeness" [OED].

Civil, literally, applies to one who fulfills the duty of a citizen; It may mean simply not rude, or observant of the external courtesies of intercourse, or quick to do and say gratifying and complimentary things. ... Courteous, literally, expresses that style of politeness which belongs to courts: a courteous man is one who is gracefully respectful in his address and manner — one who exhibits a union of dignified complaisance and kindness. The word applies to all sincere kindness and attention. [Century Dictionary, 1895]

Civil case (as opposed to criminal) is recorded from 1610s. Civil liberty "natural liberty restrained by law only so far as is necessary for the public good" is by 1640s.