We also, less commonly, have mondaine, which is the female variety of mondaine.
All these words have been borrowed from French, and they're all pronounced in French ways. Well, more or less French ways: the muscle-movements needed for talking French don't come easily to English speakers.
Anyway, never mind if you can pronounce mondain(e), can you see one?
A mondain(e) is a person who moves in fashionable circles (no, not someone with one stiletto shorter than the other, not that sort of circle) and as the whole idea of fashion is mixed up with the desire to be seen, one shouldn't be difficult to spot.
Any newspaper or celebrity magazine will give you numerous examples: the mondain(e)s will be the very thin ones with the professional smiles and the uncomfortably inadequate clothes.
That's the actress Amanda Bynes.
Once you've spotted one, go and find yourself a biscuit or a piece of cake.
And enjoy every single mouthful.
Spot the frippet: mondain(e). This French word can also mean worldly, and as well as mondain(e) it gave us the word mundane. Before it was French it was Latin: mundus means world.