ostium noun. ['ɒstɪǝm] Pl. -ia [-ɪǝ]. E17.
[Latin = door, opening, river mouth.]
1. The mouth of a river. Only in 17.

2. Anatomy & Zoology. An opening into a vessel or cavity of the body (also in mod. Latin names of particular openings); in arthropods, each of the slits or valves by which the heart opens to the body cavity; in sponges, an inhalant opening. E19.
Journal of Pediatrics At open-heart surgery..ostium primum and secundum defects were corrected.

[TahlilGaran] English Dictionary ▲