1560s, "of or pertaining to the French middle class," from French bourgeois, from Old French burgeis, borjois "town dweller" (as distinct from "peasant"), from borc "town, village," from Frankish *burg "city" (from PIE root *bhergh- (2) "high," with derivatives referring to hills and hill-forts).
Later extended to tradespeople or citizens of middle rank in other nations. Sense of "socially or aesthetically conventional; middle-class in manners or taste" is from 1764. Also (from the position of the upper class) "wanting in dignity or refinement, common, not aristocratic." As a noun, "citizen or freeman of a city," 1670s. In communist and socialist writing, "a capitalist, anyone deemed an exploiter of the proletariat" (1883).
"Bourgeois," I observed, "is an epithet which the riff-raff apply to what is respectable, and the aristocracy to what is decent." [Anthony Hope, "The Dolly Dialogues," 1907]
"But after all," Fanning was saying, "it's better to be a good ordinary bourgeois than a bad ordinary bohemian, or a sham aristocrat, or a secondrate intellectual ...." [Aldous Huxley, "After the Fireworks," 1930]