A moustache is hair that grows on the upper lip, between the nose and mouth. Men can grow moustaches naturally after puberty, though the thickness and style vary from person to person. Some moustaches are thin and trim, barely noticeable, while others are thick and bushy, curling dramatically at the ends.

Throughout history, moustaches have gone in and out of fashion. In the 1800s, many soldiers and gentlemen wore elaborate moustaches with waxed, curled ends. In the early 1900s, styles like the “handlebar” (with upturned ends) or the “walrus” (drooping down over the mouth) were popular. Famous figures like Albert Einstein, Mark Twain, and Salvador Dalí had distinctive moustaches that became part of how people recognized them.

Today, some men grow moustaches for style, while others participate in “Movember,” growing moustaches during November to raise awareness about health issues. The word can also describe something that looks like a moustache, such as when a child drinks milk and ends up with a white milk moustache on their upper lip.

The spelling “mustache” (without the u) is also common, especially in American English.