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: a pouch within an animal or plant often containing a fluid
a synovial sac
saclike adjective


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abbreviation (1)



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variant of sauk


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special agent in charge
Strategic Air Command

Examples of sac in a Sentence

Recent Examples on the Web
Castoreum is a yellowish-brown substance located in beavers’ castor sacs, which are found between the pelvis and the base of the tail. Margaret Osborne, Smithsonian Magazine, 21 Nov. 2023 Cysts In some cases, a sac next to the wisdom tooth can become filled with fluid, forming a cyst. Jake Parks, Discover Magazine, 8 Nov. 2023 He was born with a rare birth defect called an omphalocele, which means some of his organs sit in a sac outside his body. Emily Alpert Reyes, Los Angeles Times, 1 Nov. 2023 Gallstones Gallstones form in the gallbladder, a tiny sac hanging out under the liver, expelling bile as needed to digest fats. Amanda Gardner, Health, 29 Oct. 2023 To explore the sacs' origins, the researchers turned to bones from three ancestral dinosaur species. Riley Black, Scientific American, 1 Mar. 2023 Nugent said acupuncturists need expert anatomical knowledge of where the sac containing the lungs is located. Natalie Kainz, NBC News, 19 Sep. 2023 The most common causes of these blockages are abdominal adhesions (bands of scar-like tissue that form inside the abdomen), hernias (a sac formed by the lining of the intestines), certain cancers, and certain medications, the US National Library of Medicine notes. Korin Miller, SELF, 14 July 2023 Scientists on board Schmidt Ocean Institute's Falcor research ship believe the octopus is a new species of Muusoctopus, a genus of small to medium sized octopus without an ink sac, according to a news release from the organization. Gabe Hauari, USA TODAY, 3 July 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'sac.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History



French, literally, bag, from Latin saccus — more at sack

First Known Use


1741, in the meaning defined above

Time Traveler
The first known use of sac was in 1741

Dictionary Entries Near sac

Cite this Entry

“Sac.” Dictionary, Merriam-Webster, Accessed 6 Dec. 2023.

Kids Definition


: a pouch in an animal or plant often containing a fluid
a food-storage sac

Medical Definition


: a soft-walled anatomical cavity usually having a narrow opening or none at all and often containing a special fluid
a synovial sac
see air sac, amniotic sac, dental sac, lacrimal sac

More from Merriam-Webster on sac

Last Updated: - Updated example sentences
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