antrum

n. hollow space, cavity (Anatomy)

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.Examples includeantrum 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 stomachantrum follicularum  - the cavity in the epithelium that envelops the oocyte
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Antrum /an·trum/ pl. an´tra, antrums [L.] a cavity or chamber.an´tral cardiac antrum the short conical portion of the esophagus below the [more]Antrum - Community and Resources

Noun
1. a natural cavity or hollow in a bone
(hypernym) cavity, bodily cavity, cavum

n. antrum, hollow space, cavity (Anatomy)