Standard Lemma guide

sinus

noun · 10 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.

  • /ˈsaɪ.nəs/
  • Southern-England: Recorded audio is listed in the source snapshot.
  • rhymes with -aɪnəs
  • CMU ARPABET: S AY1 N AH0 S Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.

1

noun

Meaning 1

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).

Definition source: English Wiktionary via Wiktextract

Topics: anatomy, biology, medicine, natural-sciences, sciences, zoology, zootomy

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

An irregular venous or lymphatic cavity, reservoir, or dilated vessel.

Definition source: English Wiktionary via Wiktextract

Topics: anatomy, medicine, sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

3

noun

Meaning 3

An irregular venous or lymphatic cavity, reservoir, or dilated vessel.

Relating to or denoting the sinoatrial node of the heart or its function of regulating the heartbeat.

Definition source: English Wiktionary via Wiktextract

Usage: attributive

Topics: anatomy, medicine, physiology, sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

4

noun

Meaning 4

An abnormal cavity or passage such as a fistula, leading from a deep-seated infection and discharging pus to the surface.

Definition source: English Wiktionary via Wiktextract

Topics: medicine, pathology, sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

5

noun

Meaning 5

A rounded notch or depression between two lobes or teeth in the margin of a leaf or petal.

Definition source: English Wiktionary via Wiktextract

Topics: biology, botany, natural-sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

6

noun

Meaning 6

A bay of the sea; a recess in the shore.

Definition source: English Wiktionary via Wiktextract

Topics: geography, natural-sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

7

noun

Meaning 7

Synonym of sine.

Definition source: English Wiktionary via Wiktextract

Topics: mathematics, sciences, trigonometry

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: sine

Antonyms: none provided

8

noun

Meaning 8

a wide channel containing blood; does not have the coating of an ordinary blood vessel

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: venous sinus

Antonyms: none provided

Broader terms: duct, epithelial duct, canal, channel

Narrower terms: cavernous sinus, sinus cavernosus, coronary sinus, sinus coronarius, sigmoid sinus, sinus sigmoideus, straight sinus, tentorial sinus, sinus rectus, transverse sinus, sinus transversus

9

noun

Meaning 9

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

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: cavity, bodily cavity, cavum

Narrower terms: ethmoid sinus, ethmoidal sinus, sinus ethmoidales, frontal sinus, maxillary sinus, paranasal sinus, sinus paranasales, nasal sinus

10

noun

Meaning 10

an abnormal passage leading from a suppurating cavity to the body surface

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: fistula

Antonyms: none provided

Broader terms: passage, passageway

History

Etymology

Learned borrowing from Latin sinus (“a bent surface, curve, hollow”). Doublet of sine.

Across languages

Translations

43 source translations are retained for this English entry.

  • Afrikaans: sinus — pouch or cavity in a bone or other tissue
  • Afrikaans: sinusse — pouch or cavity in a bone or other tissue
  • Arabic: جَيْب اَلْأُنْف (jayb al-ʔunf) — pouch or cavity in a bone or other tissue
  • Arabic: جيوب أنفية (geyuub ʔanfeya) — pouch or cavity in a bone or other tissue
  • Asturian: senu — pouch or cavity in a bone or other tissue
  • Bulgarian: синус (sinus) — pouch or cavity in a bone or other tissue
  • Catalan: si — pouch or cavity in a bone or other tissue
  • Chinese Mandarin: 竇 /窦 (dòu) — pouch or cavity in a bone or other tissue
  • Czech: sinus — pouch or cavity in a bone or other tissue
  • Czech: dutina — pouch or cavity in a bone or other tissue
  • Esperanto: sinuso — pouch or cavity in a bone or other tissue
  • Finnish: ontelo — pouch or cavity in a bone or other tissue
  • French: sinus — pouch or cavity in a bone or other tissue
  • Galician: seo — pouch or cavity in a bone or other tissue
  • German: Sinus — pouch or cavity in a bone or other tissue
  • German: (paranasal) Nasennebenhöhle — pouch or cavity in a bone or other tissue
  • Hungarian: üreg — pouch or cavity in a bone or other tissue
  • Ido: sinuso — pouch or cavity in a bone or other tissue
  • Italian: seno — pouch or cavity in a bone or other tissue
  • Japanese: 副鼻腔 (fukubikō) — pouch or cavity in a bone or other tissue
  • Māori: pakohu — pouch or cavity in a bone or other tissue
  • Persian: کاوک (kāvak) — pouch or cavity in a bone or other tissue
  • Plautdietsch: Hollinj — pouch or cavity in a bone or other tissue
  • Polish: zatoka — pouch or cavity in a bone or other tissue
  • Portuguese: seio — pouch or cavity in a bone or other tissue
  • Romanian: sinus — pouch or cavity in a bone or other tissue
  • Russian: па́зуха (pázuxa) — pouch or cavity in a bone or other tissue
  • Spanish: seno — pouch or cavity in a bone or other tissue
  • Spanish: cavidad sinusal — pouch or cavity in a bone or other tissue
  • Spanish: seno facial — pouch or cavity in a bone or other tissue
  • Spanish: seno craneal — pouch or cavity in a bone or other tissue
  • Spanish: seno craneano — pouch or cavity in a bone or other tissue
  • Spanish: seno craniano — pouch or cavity in a bone or other tissue
  • Spanish: seno cefálico — pouch or cavity in a bone or other tissue
  • Spanish: alvéolo sinusal — pouch or cavity in a bone or other tissue
  • Spanish: alveolo sinusal — pouch or cavity in a bone or other tissue
  • Turkish: sinüs — pouch or cavity in a bone or other tissue
  • Volapük: sinud — pouch or cavity in a bone or other tissue
  • Chinese Mandarin: 竇 /窦 (dòu) — venous or lymphatic cavity
  • Chinese Mandarin: 竇性 /窦性 (dòuxìng) — relating to the sinoatrial node
  • Finnish: avanne — abnormal cavity or passage
  • Russian: свищ (svišč) — abnormal cavity or passage
  • Russian: фи́стула (fístula) — abnormal cavity or passage
Real reading context

sinus in complete knowledge articles