car·di·a 
(kärdē-ə)
(kärdē-ə)n. pl. car·di·ae (-dē-ē′) or car·di·as
1. The opening of the esophagus into the stomach.
2. The upper portion of the stomach that adjoins this opening.
[Greek kardiā, heart, cardiac orifice of the stomach; see kerd- in the Appendix of Indo-European roots.]