LATIN DICTIONARYLexicon Latīnum
noun · neutersecond declension

ōstium

ōstium n (genitive ōstiī or ōstī)
Classical[ˈoːs.ti.ũː]Ecclesiastical[ˈɔs.ti.um]
Mille Verba core vocabulary

Meaning

  1. door
  2. entrance
  3. estuary
  4. mouth (of a river)

Latīnē defined in Latin in our graded readers

iānua; per ōstium intrāmus.
ōstium -ī n — in Mille Verba, Domus et Familia
ōs flūminis, ubi in mare exit
ōstium -ī (n) — in Metamorphoses I, ch. 5
porta, aditus
ōstium -ī (n) — in Aeneis, ch. 14

Choosing the right word Döderlein's Latin Synonyms

Ostium · Janua · Fores · Valvæ

Ostium and janua denote the door, as the opening through which one goes in and out; ostium, as the most general expression for any door, like θύρα; janua, as a particular expression only for a house-door; whereas fores and valvæ denote the leaves of a door, which serve to close the opening; fores, of ordinary doors, like θυρίδες; valvæ, of stately buildings and temples, as double or folding doors. Tac. Ann. xiv. 8. Anicetus refracta janua obvios servorum adripit, donec ad fores cubiculi veniret. (v. 214.)

Declension

declension
formsingularplural
nominativeōstium
ōstiolum
ōstia
ōstiola
genitiveōstiī
ōstī, ōstiolī
ōstiōrum
ōstiolōrum
dativeōstiō
ōstiolō
ōstiīs
ōstiolīs
accusativeōstium
ōstiolum
ōstia
ōstiola
ablativeōstiō
ōstiolō
ōstiīs
ōstiolīs
vocativeōstium
ōstiolum
ōstia
ōstiola

Phrases from Meissner's Latin Phrase-Book

ostium, fores pulsare
to knock at the door.
ostium, fores aperire, claudere
to open, shut the door.

ostĭum, ii, n. kindred with Sanscr. oshtha, labium; Slav. ūsta, the same; cf. os,
I. a door (class.; cf.: porta, janua, fores, valvae).
I. Lit.: omnia istaec auscultavi ab ostio, Plaut. Merc. 2, 4, 9: observare, id. Mil. 2, 3, 81: rectum ostium, the front-door (cf. posticum), Plaut. Mil. 2, 3, 58 Brix ad loc.: aperire, to open, Ter. Heaut. 2, 3, 35: operire, to shut, id. Phorm. 5, 3, 33: obserare intus, to bolt, id. Eun. 4, 6, 25: obdere pessulum ostio, id. ib. 3, 5, 55: concrepuit ostium a Glycerio, id. And. 4, 1, 58: inscribat aliquis arse verse in ostio, Afran. ap. Fest. p. 18 Müll.: ostium limenque carceris, Cic. Tusc. 5, 5, 13: aperto ostio dormire, id. Rosc. Am. 23, 65: quaerere ab ostio, id. de Or. 2, 68, 276: exactio ostiorum, doortax, id. Fam. 3, 8, 5; v. 2. ostiarius, III.: sepulcri, Dig. 43, 23, 11.—
II. Transf., a mouth, an entrance of any kind: Acheruntis ostium in nostrost agro, Plaut. Trin. 2, 4, 124: aperto ex ostio Alti Acheruntis. Poët. ap. Cic. Tusc. 1, 16, 37: sacra Inferni ostia, Verg. G. 4, 467; id. A. 6, 109: ne in rimis areae grana oblitescant, et ostia aperiant muribus ac formicis, entrances, Varr. R. R. 1, 51, 1: portūs, Cic. Verr. 2, 4, 53, § 118: fluminis, mouth, id. Phil. 2, 11, 26; Liv. 24, 40; 44, 6; 44, 45; cf. Rhodani, Caes. B. C. 2, 1: Tiberinaque ad ostia venit, Ov. M. 15, 728; cf. Verg. A. 1, 13: Oceani, i. e. the Strait of Gibraltar, Cic. Imp. Pomp. 12, 33; Mel. 3, 9, 3.—Fig.: ego sum ostium ovium, Vulg. Johan. 10, 7.

Origins

Formed from or cognate with ōs (“mouth”).

Borrowings
  • Englishostium
  • Italianostio
  • Portugueseóstio
  • Spanishostio
Balkano-Romance
  • Romanianușă
  • Aromanianushã
  • Aromanianushi
  • Istro-Romanianușă
Italo-Romance
  • Italianuscio
Ibero-Romance
  • Spanishuzofrom Old Spanish uço
Rhaeto-Romance
  • Friulianus
  • Ladinusc
  • Romanshisch
  • Romanshesch
  • Romanshüsch
Gallo-Italic
  • Romagnolós
Gallo-Romance
  • Old Frenchhuis
Elsewhere
  • Asturianantoxanafrom Vulgar Latin *ante ostianum

Quick answers

What does ōstium mean in Latin?
ōstium, a noun, means “door; entrance; estuary”.
What is the genitive of ōstium?
The genitive singular is ōstiī. ōstium is neuter, second declension.
How do you pronounce ōstium?
In classical Latin, [ˈoːs.ti.ũː]; in ecclesiastical (church) Latin, [ˈɔs.ti.um].