ostium

noun

os·​ti·​um ˈä-stē-əm 

plural ostia ˈä-stē-ə 

: a mouthlike opening in a bodily part (such as a fallopian tube or a blood vessel)

Word History

Etymology

New Latin, from Latin, door, mouth of a river; akin to Latin os mouth — more at oral

First Known Use

1683, in the meaning defined above

Medical Definition

ostium

noun

os·​ti·​um ˈäs-tē-əm 

plural ostia -tē-ə 

: a mouthlike opening in a bodily part (as a fallopian tube or a blood vessel)

stenosis of coronary ostia

—R. L. Cecil & R. F. Loeb