demimonde \DEM-ee-mond; Fr. duh-mee-MAWND\
1. a group characterized by lack of success or status: the literary demimonde. 2. (especially during the last half of the 19th century) a class of women who have lost their standing in respectable society because of indiscreet behavior or sexual promiscuity. 3. a demimondaine. 4. prostitutes or courtesans in general. 5. a group whose activities are ethically or legally questionable: a demimonde of investigative journalists writing for the sensationalist tabloids.
It had not always been that way; it had begun as something more like a network of friends, or the part of the underground that lived in the demimonde. — Kim Stanley Robinson, Blue Mars, 2003
Although it had not been important upon her ascension to the apex of the demimonde, once there, impending poverty created a stench of failure. — Linda Berdoll, Darcy and Elizabeth, 2006
Demimode comes to English from the French demi- + monde literally meaning “half world.” The phrase was coined and popularized by Alexander Dumas, fils.