foramen ovale

https://doi.org/10.1351/goldbook.10737
  1. In the fetal heart, opening that allows shunting of blood between the right and left atria and normally closes at birth.
  2. One of the larger foramina in the base of the skull.
Source:
PAC, 2016, 88, 713. 'Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)' on page 757 (https://doi.org/10.1515/pac-2015-1202)