Etymologically
Log in

os

This is the current revision of this entry, as edited by bogdan on 16 October 2026 at 01:54. This address is a permanent link to this version.
Changes in this edit History

Pronunciation

  • IPA (Classical): [ˈoːs][1]
  • IPA (Ecclesiastical): [ˈɔs][1]

Forms

ōs n (genitive ōris); third declension[1]

Etymology

It is inherited from Proto-Italic *ōs- (“mouth”), inherited from Proto-Indo-European *h₃éh₁os (“mouth”).[2][1] Cognate with Old Irish á (“mouth”), Hittite aiš (“mouth”), Sanskrit आस् (ā́s, “mouth”) and Old English ōr (“beginning”).[2][3][1][4]

Earliest recorded meaning

De Vaan dates it from Livius Andronicus.[2] Köbler dates his career to before 200 BC.[5] Ennius and Plautus use it of the mouth.[6][3]

Semantic evolution

Its first sense was the mouth of a person or animal, and so speech and the voice.[3][1] By extension it was the head or face, the countenance and appearance.[1][7] It also meant any opening, entrance or orifice, the beak of a ship and the edge of a sword.[1][8]

Isidore says the mouth is named as if a door (ōstium), through which we put food in and spit out.[9] Its derivatives include ōsculum “kiss” and ōstium “door, mouth”.[2] Late Latin ōrālis gave English oral in the 1620s.[4]

Timeline

  • before 200 BC – Livius Andronicus uses it.[2][5]
  • c. 250–184 BC – Plautus says “snatch the pipes from his mouth”.[3][5]
  • 81–43 BC – Cicero uses it of the mouth as an organ of the senses.[6][5]
  • 1620s – English oral is recorded.[4]

Meanings

Noun

  1. The mouth.[3]
  2. Speech, voice.[1]
  3. The face, countenance, appearance.[1][7]
  4. An opening, entrance, orifice.[1]
  5. The beak of a ship; the edge of a sword.[1][8]

Word family

  • ōrārium
  • ōreae
  • ōrificium
  • ōscillum
  • ōsculum
  • cōram
  • ōrō
  • ōstium
  • English oral
  • English oracle
  • English orifice

Usage notes

A different noun Latin os, ossis meant a bone, from Proto-Indo-European *h₃ésth₁, already in the Twelve Tables.[2][3][1] Isidore notes that ōs “face” and os “bone” were both written without h.[9]

References

  1. ^ a b c d e f g h i j k l m Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f de Vaan, Michiel (2008), Etymological Dictionary of Latin and the other Italic Languages, Leiden Indo-European Etymological Dictionary Series 7, Leiden; Boston: Brill
  3. ^ a b c d e f Glare, P. G. W., ed. (2012), Oxford Latin Dictionary, 2nd ed., Oxford: Oxford University Press
  4. ^ a b c Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  5. ^ a b c d Köbler, Gerhard (2010), Lateinisches Abkunfts- und Wirkungswörterbuch für Altertum und Mittelalter, online ed., koeblergerhard.de
  6. ^ a b Lewis, Charlton T.; Short, Charles (1879), A Latin Dictionary, Oxford: Clarendon Press
  7. ^ a b Gaffiot, Félix (2016), Dictionnaire latin-français, new ed. by Gérard Gréco et al. (Gaffiot 2016), online ed.
  8. ^ a b Niermeyer, J. F. (1976), Mediae Latinitatis Lexicon Minus, Leiden: Brill
  9. ^ a b Isidore of Seville, Etymologiarum sive Originum libri XX, ed. W. M. Lindsay (Oxford, 1911).