User Contributed Dictionary
Latin
Noun
ostiumExtensive Definition
An ostium is a small opening or orifice, as in a
body organ or passage.
It can mean the following
- Any of the small openings or pores in a sponge for incoming water.
Anatomy
- Ostium of Fallopian tube.
- Ostium primum or foramen ovale (ostium secundum) of the developing heart.