A mustache that you get from sunburn or tanning by not using sunscreen. Happens to many people and looks oddly disturbing on females.
My sister has a Sunstache from getting sunburns at the beach. We tell her to put sunscreen on, but she wouldn't listen, and she was shit out of luck.
by Fuck you pay me fuckers July 16, 2014
When you have a moustache and get sunburn but then shave it off, leaving paler skin on the upper lip. Opposite of a sunstache.
Look at that faggot's reverse sunstache.
by ClemTheOctopus April 16, 2016