A word that used to mean "stylish" or "elegant", but after gross misuse by ignorant teenagers who think they're cool, has come to mean absolutely nothing. It now merely serves the purpose to annoy the sane people of the world.
Emma: "Ugh, I can't believe my parents took my license!"
Alex: "That's classy!"
Emma: "No it isn't, do you even know what classy means!"
Alex: "No, but I can use it however I want."