"suburb," late 15c. (early 15c. fabour), from Old French forsbourc, faubourg (12c.) "suburbs, outskirts," literally "that which is outside the town," from fors "outside" (from Latin foris; see foreign) + bourc "town" (a word of Frankish origin cognate with English borough). Altered in French by folk-etymology to faux bourg "false town" (suburbs were seen as inauthentic).

"characteristic of city life, pertaining to cities or towns," 1610s (but rare before 1830s), from Latin urbanus "of or pertaining to a city or city life; in Rome," also "in city fashion, polished, refined, cultivated, courteous," but also sometimes "witty, facetious, bold, impudent;" as a noun, "city dweller," from urbs (genitive urbis) "city, walled town," a word of unknown origin.

The adjective urban gradually emerged in this sense as urbane became restricted to manners and styles of expression, but originally urban also could mean "civil, courteous in manners."

Urban sprawl is recorded by 1958. Urban blight is attested by 1919. Urban renewal, euphemistic for "slum clearance," is attested from 1954, as a new U.S. program to improve low-income housing. In late 20c. American English, urban acquired a suggestion of "African-American."

Urban legend is attested by 1980.

"pertaining to or inhabiting the suburbs," 1620s, from suburb + -an. Somewhat earlier were suburbian (from Old French), suburbial (c. 1600). Latin had suburbanus "near the city" (of Rome), and in Church Latin suburbicarian was applied to the six diocese near Rome. Suburban sprawl is attested by 1939.

"the suburbs," 1874, British English, at first generally in reference to London; from suburb + -ia, perhaps on the model of utopia.

THE NIGHT NOISES OF "SUBURBIA."—The night passes calmly until the crescent moon, rising over the housetops, sheds its light on a scene of tranquility tempered only with cats. Unfortunately, Suburbia being rather sentimental, the appearance of the silvery luminary generally causes a severe conflict between rival pianos, divided from each other only by a brick and a half, while multitudinous voices, not always melodious, pay their homage to chaste Diana in hymns culled from "La Fille de Madame Augot." [London Daily News, July 28, 1874]

It is attested by 1890s in a U.S. context:

"A Street in Suburbia" would have been such a capital title for one of Mr. Bunner's stories of that district of North New Jersey whose male inhabitants daily take the 8:30 train for New York, or for a study by Mr. Howells of the social life in the environs of Boston, that one feels a pang of regret on realizing that the suburbs of Mr. Pugh's book pertain to London, and are infinitely less attractive places than Brookline and Englewood. [The Saint Paul Daily Globe, Sept. 22, 1895]

The word was associated by 1921 with U.S. sociologist Lewis Mumford (1895-1990), who shaped the image of it.

The great modern city, for the most part, does not create a common bond but a common repulsion. Suburbia—that vast and aimless drift of human beings, spreading in every direction about our cities, large and small—demonstrates the incapacity of our civilization to foster concrete ways and means for living well. [Mumford, "The Wilderness of Suburbia," The New Republic, Sept. 7, 1921]

word-forming element of Latin origin meaning "under, beneath; behind; from under; resulting from further division," from Latin preposition sub "under, below, beneath, at the foot of," also "close to, up to, towards;" of time, "within, during;" figuratively "subject to, in the power of;" also "a little, somewhat" (as in sub-horridus "somewhat rough"), from PIE *(s)up- (perhaps representing *ex-upo-), a variant form of the root *upo "under," also "up from under," which also yielded Greek hypo- and English up.

The Latin word also was used in Latin as a prefix and in various combinations. In Latin it was reduced to su- before -s- and assimilated to following -c-, -f-, -g-, -p-, and often -r- and -m-.

In Old French the prefix appears in the full Latin form only "in learned adoptions of old Latin compounds" [OED], and in popular use it was represented by sous-, sou-; as in French souvenir from Latin subvenire, souscrire (Old French souzescrire) from subscribere, etc.

The original meaning is now obscure in many words from Latin (suggest, suspect, subject, etc.). The prefix is active in Modern English; the indication generally being:

1. "under, beneath, at the bottom of;" in adverbs "down, low, lower;"

2. "inferior part, agent, division, or degree; inferior, having subordinate position" (subcontractor) also forming official titles (subaltern);

It also can indicate "division into parts or sections;" "next below, near, close to" (subantarctic); "smaller" (sub-giant); and it may be used generally as "somewhat, partial, incomplete" (subliterate).

Proto-Indo-European root meaning "under," also "up from under," hence "over."

It might form all or part of: above; assume; Aufklarung; eave; eavesdropper; hyphen; hypo-; hypochondria; hypocrisy; hypotenuse; hypothalamus; hypothesis; hypsi-; hypso-; opal; open; oft; often; resuscitate; somber; souffle; source; soutane; souvenir; sub-; subject; sublime; subpoena; substance; subterfuge; subtle; suburb; succeed; succinct; succor; succubus; succumb; sudden; suffer; sufficient; suffix; suffrage; suggestion; summon; supine; supple; supply; support; suppose; surge; suspect; suspend; sustain; up; up-; Upanishad; uproar; valet; varlet; vassal.

It might also be the source of: Sanskrit upa "near, under, up to, on," Greek hypo "under," Latin sub "under, below," Gothic iup, Old Norse, Old English upp "up, upward," Hittite up-zi "rises."