A technique attributed to a British orthodontist named Mike Mew that involves putting pressure on the roof of your mouth with your tongue to try and change the shape of your face by moving your maxilla up and forwards with the lateral pressure of your tongue. This fits into the broader looksmax approach to self-modification in the name of love and romance.

Stacy “Yh Chad has some nice ass jaw now. He’s been mewing for 6 months now”

https://www.urbandictionary.com/define.php?term=mewing