ostium

American  

[os-tee-uhm] / ˈɒs ti əm /

noun

plural

ostia

1. Anatomy, Zoology. a small opening or orifice, as at the end of the oviduct.

2. Zoology. one of the tiny holes in the body of a sponge.

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ostium British  

/ ˈɒstɪəm /

noun

1. any of the pores in sponges through which water enters the body

2. any of the openings in the heart of an arthropod through which blood enters

3. any similar opening

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Etymology

Origin of ostium

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

Example Sentences

The nasal appearances just noted are present, and if the sphenoidal sinus can be washed out and its ostium temporarily plugged, and pus rapidly reappears, its origin from these cells is probable.

From Manual of Surgery Volume Second: Extremities—Head—Neck. Sixth Edition. by Miles, Alexander

The porch of the ostium was supported by four columns delicately fluted and painted, the lower half in dull crimson, the upper in ochre.

From The Lion's Brood by Osborne, Duffield

Et quodammodo fabulantur Sarraceni, quod illo quandoque ingrediente cellulam, cellulæ ostium mutatum in ianuam valdè patentem, velut ante palatium, et gloriantur hoc primum miraculum.

From The Principal Navigations, Voyages, Traffiques and Discoveries of the English Nation — Volume 08 Asia, Part I by Hakluyt, Richard

Two or three membranous flaps, held by numerous chordae tendineae, form a true mitral valve, and allow the blood to pass through the left ostium atrioventriculare.

From Encyclopaedia Britannica, 11th Edition, Volume 3, Slice 7 "Bible" to "Bisectrix" by Various

Pathema ascended the marble steps, and passing through the richly gilded door inlaid with tortoise-shell, she stood for a moment on the mosaic floor of the ostium or entrance hall.

From The Mother of St. Nicholas A Story of Duty and Peril by Balfour, Grant