ostium

[os-tee-uh m]

noun, plural os·ti·a

[os-tee-uh] /ˈɒs ti ə/.

Anatomy, Zoology. a small opening or orifice, as at the end of the oviduct.
Zoology. one of the tiny holes in the body of a sponge.

Origin of ostium

First recorded in 1655–65, ostium is from the Latin word ōstium entrance, river mouth

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for ostium

Historical Examples of ostium

Here in the door-way, or ostium, we stop to note the "Salve!"
Historic Boys
Elbridge Streeter Brooks
The porter, who sat in a niche of the entrance-corridor (ostium).
Quintus Claudius, Volume 1 of 2
Ernst Eckstein
This will bring the anterior wall of the sinus with its ostium into view.
A System of Operative Surgery, Volume IV (of 4)
Various
Double doors admitted the visitor to the entrance-hall, or ostium.
Stories of the Olden Time
Various
With the help of cocaine the ostium can then be enlarged with various instruments.
A System of Operative Surgery, Volume IV (of 4)
Various

British Dictionary definitions for ostium

ostium

noun plural -tia (-tɪə) biology

any of the pores in sponges through which water enters the body
any of the openings in the heart of an arthropod through which blood enters
any similar opening

Word Origin for ostium

C17: from Latin: door, entrance

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

ostium in Medicine

ostium

[ŏs′tē-əm]

n. pl. os•ti•a (-tē-ə)

A small opening or orifice, as in a body organ.

Related formsos′ti•al adj.