Popularized by use as title of a comedy by Alexandre Dumas fils (1824-1895). Dumas' Demi-Monde "is the link between good and bad society ... the world of compromised women, a social limbo, the inmates of which ... are perpetually struggling to emerge into the paradise of honest and respectable ladies" ["Fraser's Magazine," 1855]. Not properly used of courtesans. Cf. 18th-century English demi-rep (1749, the second element short for reputation), defined as "a woman that intrigues with every man she likes, under the name and appearance of virtue ... in short, whom every body knows to be what no body calls her" [Fielding].
Examples from the Web for demi-monde
The principal classification of the queens of the demi-monde, however, was into "domestic" and "learned" hetr.Greek Women|Mitchell Carroll
As to the demi-monde it was the pick of America, for obvious reason.Ancestors|Gertrude Atherton
The demi-monde are fully represented upon the streets,—one of the sad but inevitable concomitants of a great city.Under the Southern Cross|Maturin M. Ballou
She reigned for a long time the recognized queen of the demi-monde.Marse Henry (Vol. 2)|Henry Watterson
She was obviously a woman of the demi-monde and probably French.December Love|Robert Hichens