Mewing is the teen trend that's driving parents up the wall. Not only a slang word, mewing is a move. According to the American Association of Orthodontists (AAO), mewing claims to be a “do-it ...

Mewing: A facial exercise meant to strengthen ... Originally describing video game characters, NPC is now used on the internet to mean people who don't think for themselves. Opp: Short for ...

The teen version of “mewing” is a “hush” symbol and touching the jawline to mean, “I can’t talk.” Lindsay tells TODAY.com that “sigma” is a classroom trend. “They say ...