Definitions

from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun A small opening or orifice, as in a body organ or passage.
  • noun Any of the small openings or pores in a sponge, through which water is drawn in.

from The Century Dictionary.

  • noun An opening or entrance; a mouth; an os.
  • noun In zoology: In sponges, the opening of an incurrent canal.

from the GNU version of the Collaborative International Dictionary of English.

  • noun (Anat.) An opening; a passage.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun A small opening or orifice, as in a body organ or passage.
  • noun Any of the small openings or pores in a sponge.

Etymologies

from The American Heritage® Dictionary of the English Language, 4th Edition

[Latin ōstium, door, opening, from ōs, mouth; see ōs- in Indo-European roots.]

Examples

Comments

Log in or sign up to get involved in the conversation. It's quick and easy.