sulcus terminalis

noun

sulcus ter·​mi·​na·​lis -ˌtər-mə-ˈnā-ləs 

plural sulci terminales -ˌlēz 

1

: a V-shaped groove separating the anterior two thirds of the tongue from the posterior third and containing the circumvallate papillae

2

: a shallow groove on the outside of the right atrium of the heart