Years ago I had known a word defined as the cleft, or dimple, in the upper lip, directly below the nose. I knew this to be a useful word, particularly for artists, since this was a facial feature requiring considerable skill to express the thoughts or emotions of the person portrayed. I accidentally came across the word in an inverse dictionary after several years of searching through books of anatomy, art, etc. I now wonder if this is the only word describing this facial feature or had I known another synonomous word. Apparently the origin of the word, philtrum, is associated with the word, philtre, a love potion, because this feature was considered a particular mark of beauty and therefore capable of arousing love. Any info will be appreciated.