philtrum
Copy
https://doi.org/10.1351/goldbook.11088
Groove in the midline of the upper lip below the nose.
Source:
PAC, 2016,
88
, 713. 'Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)' on page 792 (https://doi.org/10.1515/pac-2015-1202)