Sinus

/ˈsaɪ.nəs/

Meaning & Definition

noun
A cavity or recess, especially in the bones of the skull or the tissues of the body, often filled with air or fluid.
The maxillary sinus is located in the cheek area and is one of the largest sinus cavities.
Any of the paired cavities within the bones of the face and skull that are connected to the nasal cavity.
Sinus infections often occur when the nasal passages become blocked, leading to inflammation of the sinus cavities.
A channel or groove that carries blood in the heart or other organs.
The venous sinus collects blood from the brain and drains it into the internal jugular vein.
A fold or recess in the tissue of an organ.
The sinus of the heart allows blood to flow from the atria into the ventricles.
A sinusoidal curve or a mathematical function related to sinusoidal waveforms.
The sinus function in trigonometry is essential for understanding periodic phenomena.

Etymology

Latin 'sinus', meaning 'bay' or 'fold'.

Common Phrases and Expressions

sinus infection
An infection that occurs in the sinus cavities, often causing pain and congestion.
maxillary sinus
The largest of the paranasal sinuses, located in the maxillary bones.
frontal sinus
A paired sinus located above the eyes within the frontal bone.

Related Words

sinusitis
Inflammation of the sinus cavities.
sinogram
A representation of the sinuses in X-ray imaging.

Slang Meanings