Dictionary.com

ostium

[ os-tee-uhm ]
/ ˈɒs ti əm /
Save This Word!

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.
QUIZ
WILL YOU SAIL OR STUMBLE ON THESE GRAMMAR QUESTIONS?
Smoothly step over to these common grammar mistakes that trip many people up. Good luck!
Question 1 of 7
Fill in the blank: I can’t figure out _____ gave me this gift.

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. 2023

How to use ostium in a sentence

British Dictionary definitions for ostium

ostium
/ (ˈɒstɪəm) /

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
FEEDBACK