LATIN DICTIONARYLexicon Latīnum
noun · masculinefourth declension

sinus

sinus m (genitive sinūs)
Classical[ˈsɪ.nʊs]Ecclesiastical[ˈsiː.nus]
№ 478 of the 1,000 commonest wordsMille Verba core vocabulary

Meaning

  1. masculinepoetica bent surface; a curve, fold, hollow
  2. masculinea purse, money (which was carried in the bosom of the toga)
  3. masculinepoetica garment
    […]‘comitēs, accēdite’ dīxit‘Come, my companions,’ she said, ‘and carry back flowers with me, filling the folds of your garments.’8 CE, Ovidius, Fasti 4.431–432
  4. masculinethe bosom, breast
    Quī cum sedēns ad mēnsam nōn habēret ad manum, ubi oblātum sibi mūnus repōneret, mīsit hoc in sinum sibi.Having nowhere to put what had been brought him when sitting at the table, he shoved it into his bosom.c. 731 CE, Beda Presbyter, Historia ecclesiastica 3.2
  5. figurativelymasculinethe bosom for love, protection, asylum
  6. figurativelymasculinethe interior, inmost part of a thing
  7. figurativelymasculinea power, possession of someone
  8. figurativelymasculinea hiding place, place of concealment; a secret feeling
  9. masculinea gulf, bay, bight
    Est in sēcessū longō locus: īnsula portum efficit obiectū laterum, quibus omnis ab altōAfter long sailing comes land: here an island, its sides jutting round, forms a haven, against which every wave [coming] from the deep sea shatters, and spreads itself into the hollows of the bay.29 BCE – 19 BCE, Vergilius, Aeneis 1.159–161
  10. masculinethe land lying on or a point of land that helps to form a gulf
  11. masculinea basin, hollow, valley
  12. Medieval Latinmasculinea fjord
  13. Medieval Latinmasculinethe chord of an arc; a sine

Latīnē defined in Latin in our graded readers

pars vestis quae ante pectus pendet; etiam pars maris quae in terram intrat.
sinus -ūs m — in Mille Verba, ch. Vestis et Ōrnāmenta
pectus amplectēns
sinus -ūs (m) — in Epistulae, ch. 12

Choosing the right word Döderlein's Latin Synonyms

Gremium · Sinus

Gremium is the lap, or surface formed by the knees in a sitting posture, and figuratively the symbol of the fostering care of a mother; whereas sinus, the bosom, between the two breasts, especially in the female sex, and figuratively the symbol of protection and refuge. Cic. Pis. 37. Ætolia procul a barbaris disjuncta gentibus in sinu pacis posita medio fere Græciæ gremio continetur. (vi. 150.)

Declension

declension
formsingularplural
nominativesinussinūs
genitivesinūssinuum
sīnōrum
dativesinuīsinibus
accusativesinumsinūs
sīnōs
ablativesinūsinibus
vocativesinussinūs

Phrases from Meissner's Latin Phrase-Book

urbs in sinu sita est
the city is situate on a bay.
in sinum philosophiae compelli
to be driven into the arms of philosophy.
sinus urbis (Sall. Cat. 52. 35)
the heart of the city.
in sinu gaudere (Tusc. 3. 21. 51)
to rejoice in secret.
aliquem in sinu gestare (aliquis est in sinu alicuius) (Ter. Ad. 4. 5. 75)
to love and make a bosom friend of a person.

sĭnus, ūs, m.
I. In gen., a bent surface (raised or depressed), a curve, fold, a hollow, etc. (so mostly poet. and in postAug. prose): draco ... conficiens sinus e corpore flexos, folds, coils, Cic. poët. N. D. 2, 42, 106; so Ov. M. 15, 689; 15, 721: sinu ex togā facto, Liv. 21, 18 fin.—Of the bag of a fishing-net: quando abiit rete pessum, tum adducit sinum (piscator), Plaut. Truc. 1, 1, 15; so Juv. 4, 41; and of a hunter's net, Mart. 13, 100; Grat. Cyn. 29; also of a spider's web, Plin. 11, 24, 28, § 82.—Of the bend or belly of a sail swollen by the wind: velorum plenos subtrahis ipse sinus, Prop. 3, 9 (4, 8), 30; and so with or without velum, Tib. 1, 3, 38; Verg. A. 3, 455; 5, 831; Ov. A. A. 3, 500; Luc. 6, 472; Sil. 7, 242; Quint. 10, 7, 23; 12, 10, 37 al.—Of hair, a curl, ringlet: ut fieret torto flexilis orbe sinus, Ov. Am. 1, 14, 26; id. A. A. 3, 148.— Of the curve of a reaping-hook: falcis ea pars, quae flectitur, sinus nominatur, Col. 4, 25, 1 sq.—Of bones, a sinus: umeri, Cels. 8, 1 med.; cf. ulceris, id. 7, 2 med.: suppurationis ferro recisae, Col. 6, 11, 1; Veg. 4, 9, 3.—
II. In partic.
A. The hanging fold of the upper part of the toga, about the breast, the bosom of a garment; also the bosom of a person; sometimes also the lap (= gremium, the predom. class. signif.; esp. freq. in a trop. sense).
1. Lit.: est aliquid in amictu: quod ipsum aliquatenus temporum condicione mutatum est. Nam veteribus nulli sinus, perquam breves post illos fuerunt, Quint. 11, 3, 137; cf. decentissimus, id. 11, 3, 140 sq.: (Caesar moriens) sinistrā manu sinum ad ima crura deduxit, quo honestius caderet, Suet. Caes. 82 (for which, of the same: togam manu demisit, Val. Max. 4, 5, 6); Tib. 1, 6, 18: praetextae sinus, Suet. Vesp. 5: ne admissum quidem quemquam senatorum nisi solum et praetentato sinu, id. Aug. 35: ut conchas legerent galeasque et sinus replerent, id. Calig. 46: cedo mihi ex ipsius sinu litteras Syracusanorum, Cic. Verr. 2, 5, 57, § 147: aurum in sinu ejus invenerunt, Quint. 7, 1, 30: paternos In sinu ferens deos, Hor. C. 2, 18, 27: nuda genu, nodoque sinus collecta fluentis, Verg. A. 1, 320: et fluit effuso cui toga laxa sinu, Tib. 1, 6, 14; cf.: micat igneus ostro, Undantemque sinum nodis irrugat Iberis, Stat. Th. 4, 265: ad haec, quae a fortunā sparguntur, sinum expandit, eagerly embraces, grasps, Sen. Ep. 74, 6: aliquid velut magnum bonum intra sinum continere, id. Vit. Beat. 23, 3; cf.: sinum subducere alicui rei, to reject, id. Thyest. 430.—Prov.: sinu laxo (i. e. soluto) ferre aliquid, i. e. to be careless about a thing, Hor. S. 2, 3, 172. —
b. Transf.
(a). The purse, money, which was carried in the bosom of the toga (cf. supra, the passage, Quint. 7, 1, 30, and v. crumena; poet. and in post-Aug. prose): semper amatorum ponderat illa sinus, Prop. 2, 16 (3, 8), 12: quo pretium condat, non habet ille sinum, Ov. Am. 1, 10, 18: aere sinus plenos urbe reportare, Col. poët. 10, 310: plurium sinum ac domum inplere, Sen. Ben. 6, 43, 1: qui etiam condemnationes in sinum vertisse dicuntur ... praedam omnem in sinum contulit, into his purse, Lampr. Commod. 14 fin.: avaritiae, Juv. 1, 88.—Hence, M. Scaurus Marianis sodaliciis rapinarum provincialium sinus, the pocketer, i. e. the receiver, Plin. 36, 15, 24, § 116; cf. Tac. H. 2, 92 fin.; 4, 14.—
(b). Poet., a garment, in gen.: Tyrio prodeat apta sinu, Tib. 1, 9, 72; 1, 6, 18: auratus, Ov. F. 2, 310: purpureus, id. ib. 5, 28: regalis, id. H. 13, 36; 5, 71; Stat. S. 2, 1, 133.—
(g). The bosom of a person: manum in sinum alicui Inserere, Ter. Heaut. 3, 3, 2: gelu rigentem colubram sinu fovit, Phaedr. 4, 17, 3: opposuit sinum Antonius stricto ferro, Tac. H. 3, 10: scortum in sinu consulis recubans, Liv. 39, 43: tangitur, et tacto concipit illa sinu, i. e. utero, Ov. F. 5, 256: usque metu micuere sinus, dum, etc., id. H. 1, 45: horum in sinum omnia congerebant, Plin. Pan. 45.—
2. Trop.
a. The bosom, as in most other languages, for love, protection, asylum, etc. (usu. in the phrases in sinu esse, habere, etc.; syn. gremium): hic non amandus? hiccine non gestandus in sinu est? Ter. Ad. 4, 5, 75: iste vero sit in sinu semper et complexu meo, Cic. Fam. 14, 4, 3; cf.: postremum genus proprium est Catilinae, de ejus delectu, immo vero de complexu ejus ac sinu, id. Cat. 2, 10, 22: suo sinu complexuque aliquem recipere, id. Phil. 13, 4, 9; so (with complexus) id. ib. 2, 25, 61: (Pompeius), mihi crede, in sinu est, is very dear to me, id. Q. Fr. 2, 13, 1: Bibulum noli dimittere e sinu tuo, from your intimacy, id. ad Brut. 1, 7, 2: praesertim si in amici sinu defieas, on the bosom, Plin. Ep. 8, 16, 5: in hujus sinu indulgentiāque educatus, Tac. Agr. 4; so id. Or. 28; cf.: etsi commotus ingenio, simulationum tamen falsa in sinu avi perdidicerat, i. e. under the care or tuition, id. A. 6, 45 fin.: confugit in sinum tuum concussa respublica, i. e. into your arms, Plin. Pan. 6, 3; id. Ep. 8, 12, 1: optatum negotium sibi in sinum delatum esse dicebat, committed to his guardianship, care, Cic. Verr. 2, 1, 50, § 131; cf. Plin. Pan. 45, 2: respublica in Vespasiani sinum cessisset, Tac. H. 3, 69; 3, 19; Dig. 22, 3, 27: sinum praebere tam alte cadenti, protection, Sen. Ira, 3, 23, 6.—
b. The interior, the inmost part of a thing: alii intra moenia atque in sinu urbis sunt hostes, in the midst, in the heart of the city, Sall. C. 52, 35: in urbe ac sinu cavendum hostem, Tac. H. 3, 38; Sil. 4, 34; 6, 652; Claud. Eutr. 2, 575: ut (hostis) fronte simul et sinu exciperetur, in the centre, Tac. A. 13, 40: in intimo sinu pacis, i. e. in the midst of a profound peace, Plin. Pan. 56, 4.—
c. In sinu alicujus, in the power or possession of (postAug. and rare): opes Cremonensium in sinu praefectorum fore, Tac. H. 3, 19: omnem fortunam in sinu meo habui, Dig. 22, 3, 27.—
d. A hiding-place, place of concealment: ut in sinu gaudeant, gloriose loqui desinunt, qs. in their bosoms (or, as we say, in their sleeve), i. e. in secret, Cic. Tusc. 3, 21, 51; so of secret joy, Tib. 4, 13, 8: in tacito cohibe gaudia clausa sinu, Prop. 2, 25 (3, 20), 30; Sen. Ep. 105, 3; cf. also: plaudere in sinum, Tert. Pudic. 6: suum potius cubiculum ac sinum offerre contegendis quae, etc., the secrecy or concealment of her bed-chamber, Tac. A. 13, 13: abditis pecuniis per occultos aut ambitiosos sinus, i. e. in hidingplaces offered by obscurity or by high rank, id. H. 2, 92.—
e. Sinus Abrahae, the place of the spirits of the just (eccl. Lat.): sinum Abrahae, regionem non caelestem, sublimiorem tamen Inferis, Tert. adv. Marc. 4, 34. —
B. A bay, bight, gulf: ut primum ex alto sinus ab litore ad urbem inflectitur, Cic. Verr. 2, 5, 12, § 30; cf.: portus infusi in sinus oppidi, id. Rep. 3, 31, 43; 1, 3, 5; id. Imp. Pomp. 11, 31; Cic. Verr. 2, 5, 56, § 145; id. Att. 16, 6, 1; * Caes. B. C. 2, 32; Sall. J. 78, 2; Liv. 8, 24; Plin. 2, 43, 44, § 114 (Jahn, nivibus); Suet. Aug. 98; id. Tib. 16; Verg. A. 1, 243; 6, 132; Hor. C. 1, 33, 16; id. Epod. 10, 19.—
2. Transf.
(a). The land lying on a gulf, a point of land that helps to form it (perh. not ante-Aug.): segetibus in sinu Aenianum vastatis, Liv. 28, 5 Drak.: jam in sinum Maliacum venerat (with an army), id. 37, 6; Tac. A. 14, 9; id. H. 3, 66; id. Agr. 23; Plin. 6, 8, 8, § 23; Just. 2, 4, 26; 24, 4, 3.—
(b). A curve or fold in land, a basin, hollow, valley: Arpini terra campestri agro in ingentem sinum consedit, Liv. 30, 2, 12: subito dehiscit terra, et immenso sinu laxata patuit, Sen. Oedip. 582; id. Herc. Fur. 679; Plin. 2, 44, 44, § 115: jugum montis velut sinu quodam flexuque curvatum, Curt. 3, 4, 6: montium, id. 3, 9, 12.
sīnus, i, m., v. sinum.

Origins

Inherited from Proto-Italic *sinus, 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 جِيبَ (jība, “chord, sine”) (ultimately a loan from Sanskrit ज्या (jyā, “bowstring”)) by confusion with جَيْب (jayb, “bosom, fold in a garment”).

Elsewhere
  • Catalansina
  • Catalansinus
  • Englishsine
  • Englishsinus
  • Frenchsinus
  • GermanSinus
  • Occitansinus
  • Portuguesesino
  • Portugueseseno
  • Albaniansinus
Gallo-Romance
  • Catalansi
  • Frenchseinfrom Old French sein
Ibero-Romance
  • Portugueseseiofrom Old Galician-Portuguese sẽo
  • Spanishseno
  • Asturiansenu
  • Asturiansen
  • Galicianseofrom Old Galician-Portuguese sẽo
Insular Romance
  • Sardiniansinu
Balkano-Romance
  • Romaniansân
  • Aromaniansin
Italo-Dalmatian
  • Italianseno
  • Siciliansinu
  • Venetansen
Rhaeto-Romance
  • Friuliansen
  • Romanshsein
  • Romanshsain
  • Romanshsagn
Gallo-Italic
  • Piedmontesesen

Quick answers

What does sinus mean in Latin?
sinus, a noun, means “a bent surface; a curve, fold, hollow; a gulf, bay, bight”.
What is the genitive of sinus?
The genitive singular is sinūs. sinus is masculine, fourth declension.
How do you pronounce sinus?
In classical Latin, [ˈsɪ.nʊs]; in ecclesiastical (church) Latin, [ˈsiː.nus].