When a person flips up their shirt collar upwards. This created a new trend which can consist of not ONE, but TWO, THREE, FOUR, OR EVEN FIVE polo shirts with popped collars worn at the same time to complement each other's colors. Many times looks ridiculously stupid and gay. Most preps who wear abercrombie and shit like that prefer to "pop" their collar. Abercrombie and such prep brands promote the popped collar by advertising their polo shirts with turned collars.
"Damn i'm sweating, dude. And it's only 42 degrees!"
"That's cause you're wearing seven fucking shirts with the collars all popped up, you trend following bitch."