ostium

Borrowed from Latin ōstium.

ostium (plural ostia)

1. A small opening or orifice, as in a body organ or passage.
2. Any of the small openings or pores in a sponge.
3. The mouth of a river.

• timous

Formed from or cognate with ōs (“mouth”).^[1]

• (Classical Latin) IPA^(key): [ˈoːs.ti.ũː]
• (modern Italianate Ecclesiastical) IPA^(key): [ˈɔs.ti.um]

ōstium n (genitive ōstiī or ōstī); second declension

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

Second-declension noun (neuter).

¹Found in older Latin (until the Augustan Age).

• (door): iānua

• ōstiātim

• ōstiārius
• ōstiolum

(Note: all forms descend from a Late variant ūstium.)

• “ostium”, in Charlton T. Lewis and Charles Short (1879), A Latin Dictionary, Oxford: Clarendon Press
• “ostium”, in Charlton T. Lewis (1891), An Elementary Latin Dictionary, New York: Harper & Brothers
• "ostium", in Charles du Fresne du Cange, Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)
• “ostium”, in Gaffiot, Félix (1934), Dictionnaire illustré latin-français, Hachette.
• Carl Meißner; Henry William Auden (1894), Latin Phrase-Book‎^[1], London: Macmillan and Co.
  • to knock at the door: ostium, fores pulsare
    
  • to open, shut the door: ostium, fores aperire, claudere
    
• “ostium”, in Harry Thurston Peck, editor (1898), Harper’s Dictionary of Classical Antiquities, New York: Harper & Brothers
• “ostium”, in William Smith et al., editor (1890), A Dictionary of Greek and Roman Antiquities, London: William Wayte. G. E. Marindin