What is the groove between your nose and top lip called?

The vertical groove running from the base of the nose to the middle of the upper lip is the philtrum. The name comes from the Greek word philtron, meaning 'love charm', because the ancient Greeks regarded it as one of the most attractive parts of the face. The philtrum forms early in development in the womb, when the separate plates that make up the face grow towards each other and fuse. If they do not fuse completely, the result is a cleft lip, which is why doctors look closely at this area. In many animals, such as dogs and cats, a moist philtrum helps carry scent-laden moisture to the nose and keeps it wet, which sharpens their sense of smell. In humans, though, it is essentially a leftover of how the face is assembled and serves no major function.