antrum n : a natural cavity or hollow in a bone [also: antra (pl)]
- A cavity, especially having bony walls.
- French: antre
In Biology, "Antrum" is a general term for a cavity or chamber which may have specific meaning in reference to certain organs or sites in the body.
- antrum cardiacum - a dilation that occurs in the esophagus near the stomach (forestomach)
- mastoid antrum - Synonym: antrum mastoideum, tympanic antrum, Valsalva's antrum
- pyloric antrum - the initial portion of the pyloric part of the stomach
- antrum follicularum - the cavity in the epithelium that envelops the oocyte
antrum in German: Antrum