an·​trum ˈan-trəm How to pronounce antrum (audio)
plural antra ˈan-trə How to pronounce antrum (audio)
: an anatomical cavity within a bone (such as the maxilla) or hollow organ (such as the stomach)
antral adjective

Example Sentences

Recent Examples on the Web Each outpouching was shaped like a slice of pie, with the apex located at the antrum. Ncbi Rofl, Discover Magazine, 12 July 2011 The closer a pill lands to the antrum, the last part of the stomach before the intestine, the faster the pill begins to dissolve and find its way through the pylorus into the duodenum, the first part of the small intestine. Scott Lafee, San Diego Union-Tribune, 20 Sep. 2022

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'antrum.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History


Late Latin, from Latin, cave, from Greek antron; akin to Armenian ayr cave

First Known Use

1684, in the meaning defined above

Time Traveler
The first known use of antrum was in 1684

Dictionary Entries Near antrum

Cite this Entry

“Antrum.” Dictionary, Merriam-Webster, Accessed 5 Feb. 2023.

Medical Definition


an·​trum ˈan-trəm How to pronounce antrum (audio)
plural antra -trə How to pronounce antrum (audio)
: a cavity within a bone (as the maxilla) or hollow organ (as the stomach)

More from Merriam-Webster on antrum

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