It has a name

This week i learned a new word from the A Way With Words podcast: philtrum

Here's the definition that Martha Barnette, one of the co-hosts of the show gives at her website under her "Learn a New Word" tab.

philtrum
(FILL-trum)

The vertical groove between one's nose and upper lip.

The ancient Greeks' word for "love potion" was philtron, the source of English philter, which means the same thing.

Though no one's sure why, the Greeks also used philtron to denote the dent in one's upper lip. Some have suggested that it's because the shape of one's philtrum resembles the type of small vial used to carry such a potion. Another possibility is that it's the site on the body where such a potion was often applied.

Martha also noted an idea from Talmudic tradition with regards to this lip indentation. The tradition starts with the idea that all babies still have a perfect knowledge of God while still in the womb. (Other sources say that the unborn child has a perfect knowledge of all things in the world.) According to the Talmud (Niddah 30b) just before each child is born an angel is sent who touches the lip of each child to make the child forget. Thereby child will not be able to speak what it once knew. The indentation is there to remind us all that this life is meant for us to study and learn the things of God.