sinus

noun

Simple meaning

Any of different air-filled cavities usually in the bones of the skull.

Pronunciation

Say it like this:

synuhs

Say the bold part a little louder.

US device voice

IPA pronunciation (US)

ˈsaɪnəs

This word is pronounced essentially the same in American and British English, so one transcription covers both.

IPA (International Phonetic Alphabet) is a standard way of writing speech sounds.

Word Review

Definition

Everyday modern meanings first, grouped by part of speech.

noun

anatomyzootomy
Any of various air-filled cavities especially in the bones of the skull
anatomy
An irregular venous or lymphatic cavity, reservoir, or dilated vessel.
pathology
An abnormal passage leading from a suppurating cavity to the body surface
pathology
An abnormal cavity or passage such as a fistula, leading from a deep-seated infection and discharging pus to the surface.
anatomyzootomy
A pouch or cavity in a bone or other tissue, especially one in the bones of the face or skull connecting with the nasal cavities (the paranasal sinus).

Word at a Glance

Difficulty: B2 · Upper Intermediate (estimated)
Frequency: Moderately Common
Typical Use: Varies by meaning

Word Aura™

How this word commonly comes across.

Aura for this meaning

This meaning: Any of various air-filled cavities especially in the bones of the skull

Used this way, sinus is a specialist word that usually carries little praise or criticism of its own. This is a clinical use: it belongs to medical description, where it is factual rather than emotive.

Emotional tone: Neutral
Formality: Specialist/technical
Intensity: Not strongly marked
How common: Specialized
Connotation: Clinical and technical
Usage feel: Technical and specialized

Where it naturally appears

Medicine/healthcare
Science
Technical/specialist writing

Usage note

In general conversation this sense usually needs explaining — outside its field, people reach for a plainer word.

Nearby words

venous sinus , a specialist term, precise but narrower

Word Aura describes common impressions, not a measurement. Tone changes with sentence, speaker, relationship and situation.

More ways to use sinus

“After catching a cold, I always get a painful sinus headache that lasts days.”noun

Common Patterns and Combinations

How this word naturally appears with others.

sinus rhythmcarotid sinusmaxillary sinusfrontal sinuscoronary sinussinus nodesinus tachycardialateral sinus

Tap the highlighted word to open its own entry.

Word Family

Related forms, grouped by how they connect.

Compound terms

Established multiword terms.

sinus coronariusnounCompound term
A short sinus receiving most of the veins of the heart.
sinus ethmoidalesnounCompound term
A sinus of the meatuses of the nasal cavity (behind the bridge of the nose).
sinus headachenounCompound term
A headache resulting from congestion or infection in the paranasal sinuses.
sinus paranasalesnounCompound term
Any of the paired sinuses in the bones of the face adjacent to the nasal cavity that are lined with mucous membrane that is continuous with the lining of the nasal cavities.
sinus rectusnounCompound term
An unpaired sinus of the dura mater.
sinus sigmoideusnounCompound term
An S-shaped dural sinus on the temporal and occipital bones.

Related words

Connected by subject or meaning, not by word formation.

sinusitisnounRelated term
Inflammation of one of the paranasal sinuses.

More about this wordSynonyms, forms, origin

Synonyms

Sense: any of various air-filled cavities especially in the bones of the skull

venous sinusTechnical

Ask Vocabaura

Understand the word your way.

What Does It Mean Here?

Words can change meaning depending on context.

Use it yourself

Knowing “sinus” starts when you use it. Pick a next step, all free.

Know the meaning? Practice using it in a real situation, free, no credits.

Dictionary data from Wiktionary via the Free Dictionary API. Simple meanings, combinations and word intelligence are built from verified reference data, no AI is used to load this page.