os·​ti·​um | \ ˈä-stē-əm How to pronounce ostium (audio) \
plural ostia\ ˈä-​stē-​ə How to pronounce ostia (audio) \

Definition of ostium

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

First Known Use of ostium

1683, in the meaning defined above

History and Etymology for ostium

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

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Time Traveler for ostium

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The first known use of ostium was in 1683

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Cite this Entry

“Ostium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ostium. Accessed 12 Jul. 2020.

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os·​ti·​um | \ ˈäs-tē-əm How to pronounce ostium (audio) \
plural ostia\ -​tē-​ə How to pronounce ostia (audio) \

Medical Definition of ostium

: 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

More from Merriam-Webster on ostium

Britannica.com: Encyclopedia article about ostium

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