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)

Examples of sinus in a Sentence

Recent Examples on the Web Different groups of plants emit pollen to reproduce at various times of the year, causing respiratory and sinus symptoms in some people. Hayleigh Evans, The Arizona Republic, 21 Sep. 2024 Unwelcome objects — like pollen, pet dander, dust motes, and viral particles — enter our sinuses all the time. Cody Cottier, Discover Magazine, 8 Aug. 2024 Then comes shedding and pollen season, leaving your sinuses no relief in sight. Christina Shepherd McGuire, Better Homes & Gardens, 6 Aug. 2024 Plus, staying hydrated allows the cilia in the nose to do their job and push things like bacteria and viruses out of the sinuses, which also can prevent infection. Amanda Rock, Parents, 30 July 2024 See all Example Sentences for sinus 

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 8 Oct. 2024.

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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