sinus

[ sahy-nuhs ]

noun

, plural si·nus·es.

1. a curve; bend.
2. a curving part or recess.
3. Anatomy.
   1. any of various cavities, recesses, or passages, as a hollow in a bone, or a reservoir or channel for venous blood.
   2. one of the hollow cavities in the skull connecting with the nasal cavities.
   3. an expanded area in a canal or tube.
4. Pathology. a narrow passage leading to an abscess or the like.
5. Botany. a small, rounded depression between two projecting lobes, as of a leaf.

sinus

/ ˈsaɪnəs /

noun

1. anatomy
   1. any bodily cavity or hollow space
   2. a large channel for venous blood, esp between the brain and the skull
   3. any of the air cavities in the cranial bones
2. pathol a passage leading to a cavity containing pus
3. botany a small rounded notch between two lobes of a leaf, petal, etc
4. an irregularly shaped cavity

sinus

/ sī′nəs /

1. A cavity or hollow space in a bone of the skull, especially one that connects with the nose.
2. A channel for the passage of a body fluid, such as blood.

Other Words From

• sinus·like adjective

Word History and Origins

Origin of sinus¹

1590–1600; < Latin sinus (stem sinu- ) bent or curved surface, curve, fold

Word History and Origins

Origin of sinus¹

C16: from Latin: a curve, bay

Example Sentences

About two-thirds of people who develop the syndrome experience symptoms several days or weeks after they have fallen ill with diarrhea or a lung or sinus illness.

From Washington Post

One man had developed brain sinus clots during the shot’s clinical trial and a seventh case is under investigation, the pharmaceutical company said during the meeting.

From Science News

An independent safety review of the new data revealed no connection to blood clots and reported no cases of sinus clots, the company said in the March 22 statement.

From Science News

Eighteen patients who received the vaccine developed blood clots in the sinuses that drain blood from the brain, a potentially deadly condition called cerebral venous sinus thrombosis.

From Science News

Otherwise, besides the dual assault of pollen and dryness on our sinuses, things are good.

From Washington Post

A fair number explicitly ask for an antibiotic, to cover the possibility that it is “bronchitis” or a “sinus infection.”

From The Daily Beast

Benign secondary headaches include headaches associated with the cold, flu, or sinus infections.

From The Daily Beast

First of all, migraines often are misdiagnosed as sinus headaches.

From The Daily Beast

One of the entries reads: “I spoke with a doctor for a long time about my sinus infections.”

From The Daily Beast

I suffered intense sinus flare-ups, headaches, high blood pressure, wheezes, and coughs.

From The Daily Beast

Sinus duo sunt maiores, vastque; alter is, qui S. Laurentij gurges; alter, qui Francius appellatur.

From Project Gutenberg

Dr Klein's account of the origin of the sinus terminalis is quite correct.

From Project Gutenberg

From the first the sinus terminalis possesses cellular walls, as is clear from its mode of origin.

From Project Gutenberg

Cory and Kelly, sixty-eight ounces of blood was removed from the sinus, by aspiration.

From Project Gutenberg

The fluid in the sinus has increased gradually since the evacuation of it with the aspirator.

From Project Gutenberg