sinus

[sahy-nuhs]

noun

plural

sinuses 

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

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 Word Forms

• sinuslike 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