sinus

noun

si·​nus ˈsī-nəs How to pronounce sinus (audio)
: cavity, hollow: such as
a
: a narrow elongated tract extending from a focus of suppuration and serving for the discharge of pus
b(1)
: a cavity in the substance of a bone of the skull that usually communicates with the nostrils and contains air
(2)
: a channel for venous blood
(3)
: a dilatation in a bodily canal or vessel
c
: a cleft or indentation between adjoining lobes (as of a leaf or corolla)

Example Sentences

Recent Examples on the Web Unfortunately, with the winter also comes winter sinus issues like coughs and colds. Dallas News, 12 Jan. 2023 Chrissi Kelly, now an advocate in Britain for treatment of smell disorders, lost her smell following a sinus infection in 2012. Nicole Kagan, Los Angeles Times, 29 Sep. 2022 Adding humidity back into the air helps remedy dry nasal and sinus passages, Clifford W. Bassett, MD, medical director of Allergy and Asthma Care of New York, previously told Health. Chloe Irving, Health.com, 11 Oct. 2021 Symptoms of breakthrough infections can include significant sinus and nasal congestion, runny nose, sore throat and low-grade fever, Sullivan said. Jennifer Dixon, Detroit Free Press, 30 Sep. 2021 This miniature humidifier, which is about the size of a tumbler, will keep nosebleeds, sinus infections, and tight, flaky skin at bay. Brittney Morgan, housebeautiful.com, 5 May 2023 Respiratory viruses can lead to sinus infections, which can predispose kids to brain abscesses, Rodgers explained. Aria Bendix, NBC News, 28 Apr. 2023 Sood says brain abscesses normally follow a very small percentage of sinus infections and inner ear infections in kids. Brenda Goodman, CNN, 28 Apr. 2023 Brain abscesses can follow a very small percentage of sinus infections and inner ear infections among kids, Sood told CNN. Claire Thornton, USA TODAY, 28 Apr. 2023 See More

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

Word History

Etymology

Middle English, from Medieval Latin, from Latin, curve, fold, hollow

First Known Use

15th century, in the meaning defined above

Time Traveler
The first known use of sinus was in the 15th century

Dictionary Entries Near sinus

Cite this Entry

“Sinus.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/sinus. Accessed 29 May. 2023.

Kids Definition

sinus

noun
si·​nus ˈsī-nəs How to pronounce sinus (audio)
: a hollow place : cavity
especially : any of several cavities in the skull that usually connect with the nostrils

Medical Definition

sinus

noun
si·​nus ˈsī-nəs How to pronounce sinus (audio)
: a cavity or hollow in the body: as
a
: a narrow elongated tract extending from a focus of suppuration and serving for the discharge of pus
a tuberculous sinus
b(1)
: a cavity in the substance of a bone of the skull that usually communicates with the nostrils and contains air
(2)
: a channel for venous blood
(3)
: a dilatation in a bodily canal or vessel

More from Merriam-Webster on sinus

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