Philtrum

philtrum \ˈfil-trəm\ noun: 1. the midline groove that runs from the top of the lip to the nose, 2. a philter

Etymology: Latin philtrum love philter, from Greek philtron love philter, dimple in upper lip (from the ancient Greeks’ view that the philtrum was an erogenous part of the body)

I’m incapable of growing hair on my philtrum, so I could never sport a moustache in the style of Charlie Chapman or Adolf Hitler.