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

Her debut with Warren was a majority points win over Elhem Mekhaled last July despite Cameron saying she had a "sinus and chest infection" the week of the fight.

From BBC

The photograph captures Sinus Iridum - also known as the Bay of Rainbows - a massive crater 260km across.

From BBC

"Shadow peaks of Sinus Iridum" by Gábor Balázs, from Hungary, took the top spot in the Our Moon category.

From BBC

He died 10 days later of cerebral venous sinus thrombosis.

From BBC

At Marina's inquest in December 2023, a coroner determined her death had been caused by a combination of factors: intracerebral haemorrhage, cerebral venous sinus thrombosis, and vaccine-induced immune thrombocytopenia and thrombosis due to the AstraZeneca vaccine.

From BBC