Demimonde

A most remarkable instance of this was afforded in the play of Camille by the performance of the supper-scene. The stage in this scene is supposed to represent a supper-room, enlivened by the presence of a party of young Parisians, more gay, indeed, than respectable, but still Parisians, and Parisians of the demimonde, which, of the two halves that go to make up the whole of the monde, preserves the hemisphere of manners while it throws away the hemisphere of decorum.

Source: wiktionary

To give a good and solid education to the gentle sex would tend to double the army of progress, to draw closer the domestic relations, and to annihilate that extra-conjugal society (the demi[-]monde of [Alexandre] Dumas the younger) which is now so very prosperous.

Source: wiktionary

Paris society borrows fashions from the demi-monde, and the demi-monde borrows manners from the extravagant princesses, countesses, and viscountesses. All Parie has been stirred with the Sardanapalian entertainment, which a leader of the demi-monde gave on the eve of Lent to the best male society in the Empire. The ladies were all unquestionably from young [Alexandre] Dumas' panier à quinze sous; but their manners and their toilettes were, we are told, all that could be desired.

Source: wiktionary

Skating Rinks are chiefly patronised by members of the demi[-]monde.

Source: wiktionary