sinus
noun
si·nus
| \ ˈsī-nəs
\
\
Definition of sinus
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
This tends to happen when people are in splashy water parks, jet-skiing, or irrigating their sinuses with tap water that hasn’t been disinfected, boiled, or filtered. — Beth Mole, Ars Technica, "Brain-eating amoeba kills again—here’s how it kills and how to avoid it," 26 July 2019 My sinuses are extremely irritated during certain times of the year and the salt room with its relaxing environment is especially beneficial to me. — Deborah Storey | For Al.com, al, "Huntsville salt therapy spa part of nationwide trend," 25 July 2019 My sinuses, on the other hand, weren't feeling much better. — Sarah Watts, NBC News, "Does salt therapy actually work? I tried it to help ease my summer allergies," 23 July 2019 Brother Sage is a believer in urine therapy and has practiced this technique for decades, using urine to wash his eyes, clean his feet and clear out his sinuses. — Kai Beech, The Denver Post, "A urine therapy group in Colorado touts the benefits of drinking your own pee. Doctors disagree," 23 July 2019 After D'wan Mathis complained of headaches and severe sinus pain, Georgia's medical director Ron Courson recognized the signs of a cyst and rushed Mathis to the emergency room. — Tess Demeyer, USA TODAY, "Father of Georgia QB D'Wan Mathis says school saved son's life with brain surgery," 12 May 2019 This type of infection often stems from an untreated sinus or ear infection. — Julia Michie Bruckner, Discover Magazine, "Is a Teen's Pain Just Drama, or Something Worse?," 12 Mar. 2019 The smell of jet fuel mixed with animal and human waste and burning charcoal fires created a heady perfume that coated the sinuses. — Mark Curnutte, Cincinnati.com, "From the archives: Reaching out to Haiti, coverage of 2010 earthquake," 13 Jan. 2018 But occasionally, infections can occur in a region called the sphenoid sinus, located behind the eyes near the optic nerve. — Amanda Macmillan, Health.com, "A 13-Year-Old Died After a Sinus Infection Traveled to His Brain. How Does That Happen?," 16 Mar. 2018These example sentences are selected automatically from various online news sources to reflect current usage of the word 'sinus.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
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More Definitions for sinus
sinus
noun
English Language Learners Definition of sinus
: any of several spaces in the skull that connect with the nostrils
See the full definition for sinus in the English Language Learners Dictionary
sinus
noun
si·nus
| \ ˈsī-nəs
\
\
Kids Definition of sinus
: any of several spaces in the skull mostly connected with the nostrils
sinus
noun
si·nus
| \ ˈsī-nəs
\
\
Medical Definition of sinus
: 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
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