# sinus
## English
### Etymology

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

### Pronunciation

* IPA: /ˈsaɪ.nəs/
* Audio (Southern England):(file)
* Rhymes: -aɪnəs

### Noun

sinus (plural sinuses)
* (anatomy, zootomy) 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).
    Hyponyms: ethmoid sinus, frontal sinus, maxillary sinus, paranasal sinus, piriform sinus, Rokitansky-Aschoff sinus, sphenoid sinus
* (anatomy) An irregular venous or lymphatic cavity, reservoir, or dilated vessel.
    Hyponyms: carotid sinus, cavernous sinus, coronary sinus, lateral sinus, petrosal sinus, sagittal sinus, sigmoid sinus, straight sinus, transverse sinus, venous sinus
** (physiology, attributive) Relating to or denoting the sinoatrial node of the heart or its function of regulating the heartbeat.
* (pathology) An abnormal cavity or passage such as a fistula, leading from a deep-seated infection and discharging pus to the surface.
* (botany) A rounded notch or depression between two lobes or teeth in the margin of a leaf or petal.
* (geography) A bay of the sea; a recess in the shore.
* (trigonometry) Synonym of sine.
** 1884 November 29, “Aerial Navigation”, in Scientific American: A Weekly Journal of Practical Information, Art, Science, Mechanics, Chemistry, and Manufactures, volume LI, number 22, New York, N.Y.: Munn & Co., translation of original by Victor Tatin in La Nature, page 342, column 1:So, in the helicopteron, as the helix is at the same time a sustaining plane, it should be likened to a surface moving horizontally, and in which, consequenty, the resistance to motion will be to the lifting power as the sinus is to the cosinus of the angle formed by such plane with the horizon.
** 1996, Pentti Zetterberg, Matti Eronen, Markus Lindholm, “Construction of a 7500-Year Tree-Ring Record for Scots Pine (Pinus sylvestris, L.) in Northern Fennoscandia and its Application to Growth Variation and Palaeoclimatic Studies”, in Heinrich Spiecker, Kari Mielikäinen, Michael Köhl, Jens Peter Skovsgaard, editors, Growth Trends in European Forests (European Forest Institute Research Report; No. 5), Springer-Verlag Berlin Heidelberg, →ISBN, page 15:The variations are described in terms of cycles of sinuses and cosinuses.
** 2007, Vladimir G. Ivancevic, Tijana T. Ivancevic, “Introduction: Human and Computational Mind”, in Computational Mind: A Complex Dynamics Perspective (Studies in Computational Intelligence; 60), Springer-Verlag Berlin Heidelberg, →ISBN, →LCCN, section 1 (Natural Intelligence and Human Mind), pages 60–61:Basically, the rotation of the matrix of the factor loadings L represents its post-multiplication, i.e. L* = LO by the rotation matrix O, which itself resembles one of the matrices included in the classical rotational Lie groups SO(m) (containing the specific m–fold combination of sinuses and cosinuses.

#### Derived terms

* confluence of sinuses
* dural sinus
* dural venous sinus
* extrasinus
* inferior petrosal sinus
* inferior sagittal sinus
* intrasinus
* nonsinus
* parasinus
* pyriform sinus
* sick sinus syndrome
* sinal
* sino-, sinu-, sinuso-
* sinus brady
* sinuscope
* sinusectomy
* sinusitis
* sinuslike
* sinus node
* sinusoid
* sinus pudoris
* sinus rhythm
* sinus tachy
* sinus tachycardia
* sinus venosus
* sphenoidal sinus
* superior petrosal sinus
* superior sagittal sinus
* urogenital sinus

#### Translations
### References

* “sinus”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.
* “sinus”, in Merriam-Webster Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.

### Anagrams

* Sunis, nisus

## Albanian
### Etymology

Learned borrowing from Latin sinus.

### Noun

sinus m
* (trigonometry) sine

### Further reading

* “sinus”, in FGJSH: Fjalor i gjuhës shqipe [Dictionary of the Albanian language] (in Albanian), 2006
* FGJSSH: Fjalor i gjuhës së sotme shqipe [Dictionary of the modern Albanian language]‎, 1980

## Catalan
### Etymology

Learned borrowing from Latin sinus.

### Pronunciation

* IPA: (Central, Balearic, Valencia) [ˈsi.nus]

### Noun

sinus m (invariable)
* sine

#### Derived terms

* cosinus

### See also

* tangent
* cosecant
* secant
* cotangent

### Further reading

* “sinus” in Diccionari de la llengua catalana, segona edició, Institut d’Estudis Catalans.

## Czech
### Etymology

Learned borrowing from Latin sinus.

### Pronunciation

* IPA: [ˈsɪnus]
* Hyphenation: si‧nus

### Noun

sinus m inan
* (trigonometry) sine
* (anatomy) sinus

#### Related terms

* kosinus

### Further reading

* “sinus”, in Příruční slovník jazyka českého (in Czech), 1935–1957
* “sinus”, in Slovník spisovného jazyka českého (in Czech), 1960–1971, 1989
* sinus in Akademický slovník cizích slov, 1995, at prirucka.ujc.cas.cz

## Danish
### Etymology

Learned borrowing from Latin sinus.

### Noun

sinus c (singular definite sinussen, plural indefinite sinusser)
* (trigonometry) sine

## Dutch
### Etymology

Learned borrowing from Latin sinus.

### Pronunciation

* Audio:(file)
* Hyphenation: si‧nus

### Noun

sinus m (plural sinussen, diminutive sinusje n)
* (trigonometry) sine
* sinus

#### Descendants

* → Indonesian: sinus
* → Papiamentu: sinùs

## French
### Etymology

Learned borrowing from Latin sinus. Doublet of sein.

### Pronunciation

* IPA: /si.nys/
* Audio:(file)

### Noun

sinus m (plural sinus)
* (anatomy) sinus
* (trigonometry) sine

### See also

* cosécante
* cosinus
* cotangente
* sécante
* tangente

### Further reading

* “sinus”, in Trésor de la langue française informatisé [Digitized Treasury of the French Language], 2012.

## Indonesian
### Etymology

Borrowed from Dutch sinus, from Latin sinus.

### Pronunciation

* IPA: [ˈsinʊs]
* Rhymes: -nʊs, -ʊs, -s
* Hyphenation: si‧nus

### Noun

sinus (plural sinus-sinus)
* sinus:
** (anatomy) 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).
** (pathology) an abnormal cavity or passage such as a fistula, leading from a deep-seated infection and discharging pus to the surface.
* (trigonometry) sine: in a right triangle, the ratio of the length of the side opposite an angle to the length of the hypotenuse.

#### Derived terms

* sinus etmoid
* sinus frontalis
* sinus maksila
* sinus maksilaris
* sinus stenoid

### Further reading

* “sinus” in Kamus Besar Bahasa Indonesia, Jakarta: Agency for Language Development and Cultivation – Ministry of Education, Culture, Research, and Technology of the Republic of Indonesia, 2016.

## Latin
### Etymology 1

From Proto-Indo-European *sinos; akin to Albanian gji (“breast, bosom”).
The mathematical sense ‘chord of an arc, sine’ was introduced in the 12th century by Gherardo of Cremona as a semantic loan from Arabic جَيْب (jayb, “chord, sine”) (ultimately a loan from Sanskrit ज्या (jyā, “bowstring”)) by confusion with جَيْب (jayb, “bosom, fold in a garment”).

#### Pronunciation

* (Classical Latin) IPA: /ˈsi.nus/, [ˈs̠ɪnʊs̠]
* (modern Italianate Ecclesiastical) IPA: /ˈsi.nus/, [ˈsiːnus]

#### Noun

sinus m (genitive sinūs); fourth declension
* (chiefly poetic) a bent surface; a curve, fold, hollow
* (literal) the hanging fold of a toga over the breast; a pocket, lap
    Synonym: gremium
** (transferred sense)
*** a purse, money, which was carried in the bosom of the toga
*** (poetic) a garment
**** 8 CE, Ovid, Fasti 4.431–432:‘comitēs, accēdite’ dīxit ‘et mēcum plēnōs flōrē refertē sinūs.’‘‘Come, my companions,’’ she said, ‘‘and with me you all [can] carry back flowers, filling the folds of your garments.’’ (Persephone and her attendants wander away from the protection of her mother Ceres and the other matrons prior to Persephone’s abduction.)
*** the bosom, breast
    Synonym: pectus
**** Beda Venerabilis, Historia Ecclesiastica gentis Anglorum III.2:Qui cum sedens ad mensam non haberet ad manum, ubi oblatum sibi munus reponeret, misit hoc in sinum sibi.Having nowhere to put what had been brought him when sitting at the table, he shoved it into his bosom.
** (figurative)
*** the bosom for love, protection, asylum
*** the interior, inmost part of a thing
*** a power, possession of someone
*** a hiding place, place of concealment; a secret feeling
* a gulf, bay, bight
** 29 BCE – 19 BCE, Virgil, Aeneid 1.160–161:[insula] quibus omnis ab altō frangitur inque sinūs scindit sēsē unda reductōs.[an island] against which every wave [coming] from the deep sea shatters, and [thus] diminished, spreads itself into the bay.
** the land lying on or a point of land that helps to form a gulf
** a basin, hollow, valley
** (Medieval Latin) a fjord
* (Medieval Latin, mathematics) the chord of an arc; a sine
* This entry needs quotations to illustrate usage. If you come across any interesting, durably archived quotes then please add them!

##### Inflection

Fourth-declension noun.

##### Quotations

Aeneid (Pūblius Vergilius Marō) lines 1.160–161: Latin: quibus omnis ab altō // frangitus inque sinūs scindit sēsē͡ unda reductōs. English: on which all the waves from the deep are broken and it splits itself into receeding ripples.

##### Derived terms

* sinuō (verb)
* sinuōsus (adjective)

##### Descendants

* → Aromanian: sin
* Asturian: senu, sen
* Catalan: si; → sina
* → English: sinus, sine
* French: sein; → sinus
* Friulian: sen
* Hebrew: סינוס
* Italian: seno
* Old Galician-Portuguese: sẽo, seo
** Galician: seo
** Portuguese: seio
* Piedmontese: sen
* → Portuguese: sino, seno (learned)
* Romanian: sân
* Romansch: sain
* Sardinian: sinu
* Sicilian: sinu
* Spanish: seno
* Venetan: sen

### Etymology 2

From Proto-Indo-European *sh₁ih₂sno-, deverbative of *seh₁y- (“to sift, strain”) (compare Ancient Greek ἠθέω (ēthéō), Lithuanian sijóti, Serbo-Croatian sȉjati).

#### Alternative forms

* sīnum

#### Pronunciation

* (Classical Latin) IPA: /ˈsiː.nus/, [ˈs̠iːnʊs̠]
* (modern Italianate Ecclesiastical) IPA: /ˈsi.nus/, [ˈsiːnus]

#### Noun

sīnus m (genitive sīnī); second declension
* a large round drinking vessel with swelling sides, shaped like a bowl
* This entry needs quotations to illustrate usage. If you come across any interesting, durably archived quotes then please add them!

##### Inflection

Second-declension noun.

### References

* ↑ De Vaan, Michiel (2008) “sinus”, in Etymological Dictionary of Latin and the other Italic Languages (Leiden Indo-European Etymological Dictionary Series; 7), Leiden, Boston: Brill, →ISBN, page 567
* ↑ Douglas Q. Adams (1997) “Sieve”, in J. P. Mallory, Douglas Q. Adams, editors, Encyclopedia of Indo-European Culture, London: Fitzroy Dearborn, page 518

### Further reading

* “sinus”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
* “sinum”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
* “sinus”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
* "sinus", in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)
* sinus in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.
* Carl Meißner, Henry William Auden (1894) Latin Phrase-Book‎, London: Macmillan and Co. the heart of the city: sinus urbis (Sall. Cat. 52. 35) the city is situate on a bay: urbs in sinu sita est to rejoice in secret: in sinu gaudere (Tusc. 3. 21. 51) to love and make a bosom friend of a person: aliquem in sinu gestare (aliquis est in sinu alicuius) (Ter. Ad. 4. 5. 75) (ambiguous) to be driven into the arms of philosophy: in sinum philosophiae compelli
* “sinus”, in Harry Thurston Peck, editor (1898), Harper's Dictionary of Classical Antiquities, New York: Harper & Brothers
* “sinus”, in William Smith, editor (1854, 1857), A Dictionary of Greek and Roman Geography, volume 1 & 2, London: Walton and Maberly

## Northern Sami
### Pronunciation

* This entry needs pronunciation information. If you are familiar with the IPA then please add some!

### Noun

sinus
* locative singular of sitnu

## Norwegian Bokmål
### Etymology

Learned borrowing from Latin sinus.

### Noun

sinus m (definite singular sinusen, indefinite plural sinuser, definite plural sinusene)
* (trigonometry) sine
* (anatomy) sinus

#### Related terms

* cosinus

### References

* “sinus” in The Bokmål Dictionary.

## Norwegian Nynorsk
### Etymology

Learned borrowing from Latin sinus.

### Noun

sinus m (definite singular sinusen, indefinite plural sinusar, definite plural sinusane)
* (trigonometry) sine
* (anatomy) sinus

#### Related terms

* cosinus

### References

* “sinus” in The Nynorsk Dictionary.

## Polish
### Etymology

Learned borrowing from New Latin sinus.

### Pronunciation

* IPA: /ˈsi.nus/
* Audio:(file)
* Rhymes: -inus
* Syllabification: si‧nus

### Noun

sinus m inan (related adjective sinusowy)
* (trigonometry) sine, sinus (in a right triangle, the ratio of the length of the side opposite an angle to the length of the hypotenuse)
    Hypernym: funkcja trygonometryczna
    Coordinate terms: cosecans, cosinus, cotangens, secans, tangens

#### Related terms

* sinusoidalny
* sinusoidalnie
* sinusoida

### Further reading

* sinus in Wielki słownik języka polskiego, Instytut Języka Polskiego PAN
* sinus in Polish dictionaries at PWN

## Romanian
### Etymology

Borrowed from French sinus, from Latin sinus.

### Noun

sinus n (plural sinusuri)
* sine (trigonometric function)

## Swedish
### Etymology

Learned borrowing from Latin sinus.

### Noun

sinus c
* (trigonometry) sine
* (anatomy) sinus

#### Declension

No inflected forms. sinus is used for the definite singular.

### Further reading

* sinus in Svenska Akademiens ordlista (SAOL)
* sinus in Svensk ordbok (SO)
* sinus in Svenska Akademiens ordbok (SAOB)

## Veps
### Pronoun

sinus
* inessive of sinä