"Strike a pose," sang Madonna in her most famous song, "Vogue." But if the pose you're striking is fake, pretentious, or arrogant, you're a poseur. Be yourself: it's cooler.
It's one thing to be smart, funny, or cool. It's another thing to pretend to be that way: that's the life of a poseur. (Say it in the French way: poh-ZUHR.) It's all too easy to spot a poseur from their ridiculous posing. Why poseurs think that they come across as anything other than fake is beyond me. They must be really insecure to think they need to pretend to be something they're not. Every once in a while, though, a poseur can fake it till they make it. Then they're no longer a poseur.