suburb n.

word-forming element 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." The Latin word also was used as a prefix and in various combinations.

In Latin 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 obscured in many words from Latin (suggest, suspect, subject, etc.). The prefix is active in Modern English, sometimes meaning "subordinate" (as in subcontractor); "inferior" (17c., as in subhuman); "smaller" (18c.); "a part or division of" (c. 1800, as in subcontinent).

"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 word gradually emerged in this sense as urbane became restricted to manners and styles of expression. In late 20c. American English gradually acquiring a suggestion of "African-American." Urban renewal, euphemistic for "slum clearance," is attested from 1955, American English. Urban sprawl recorded by 1958. Urban legend attested by 1980.