sin city n.

Middle English sinne, from Old English synn, syn "violation of divine law, offense against God; moral wrongdoing," also "injury, mischief; enmity, feud; guilt, crime, misdeed," from Proto-Germanic *sundiō "sin" (source also of Old Saxon sundia, Old Frisian sende, Middle Dutch sonde, Dutch zonde, German Sünde "sin, transgression, trespass, offense," extended forms).

The notion is probably ultimately "it is true," i.e. "the sin is real" (compare Gothic sonjis, Old Norse sannr "true"), from PIE *snt-ya-, a collective form from *es-ont- "becoming," present participle of the root *es- "to be."

The semantic development would be via the notion of "to be truly the one (who is guilty)," as in Old Norse phrase verð sannr at "be found guilty of," and the use of the phrase "it is being" in Hittite confessional formula. The same process probably yielded the Latin word sons (genitive sontis) "guilty, criminal" from present participle of sum, esse "to be, that which is." Some etymologists believe the Germanic word was an early borrowing directly from the Latin genitive. Also see sooth.

The details of the purely theological definition are much contested. Sin-eater is attested from 1680s, "one who, for pay, takes on the sins of a deceased person," typically by eating certain food in the presence of the corpse. To live in sin "cohabit without marriage" is from 1838; the phrase was used since Middle English in a more general sense (to sin with has been "commit fornication or adultery with" since c. 1200). Ice hockey slang sin bin "penalty box" is attested from 1950.

c. 1200, from Old French cite "town, city" (10c., Modern French cité), from earlier citet, from Latin civitatem (nominative civitas; in Late Latin sometimes citatem) originally "citizenship, condition or rights of a citizen, membership in the community," later "community of citizens, state, commonwealth" (used, for instance of the Gaulish tribes), from civis "townsman," from PIE root *kei- (1) "to lie," also forming words for "bed, couch," and with a secondary sense of "beloved, dear."

Now "a large and important town," but originally in early Middle English a walled town, a capital or cathedral town. Distinction from town is early 14c. OED calls it "Not a native designation, but app[arently] at first a somewhat grandiose title, used instead of the OE. burh"(see borough).

Between Latin and English the sense was transferred from the inhabitants to the place. The Latin word for "city" was urbs, but a resident was civis. Civitas seems to have replaced urbs as Rome (the ultimate urbs) lost its prestige. Loss of Latin -v- is regular in French in some situations (compare alleger from alleviare; neige from nivea; jeune from juvenis. A different sound evolution from the Latin word yielded Italian citta, Catalan ciutat, Spanish ciudad, Portuguese cidade.

London is the city from 1550s. As an adjective, "pertaining to a city, urban," from c. 1300. City hall "chief municipal offices" is first recorded 1670s; to fight city hall is 1913, American English. City slicker "a smart and plausible rogue, of a kind usu. found in cities" [OED] is first recorded 1916 (see slick (adj.)). City limits is from 1825.

The newspaper city-editor, who superintends the collection and publication of local news, is from 1834, American English; hence city desk attested from 1878. Inner city first attested 1968.