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ianuarius

Etymology and origin of the Latin word ianuarius

History Permalink
Confidence
Established
Formation
Derivation
First attested
Varro
Ultimate origin
Latin (Iānus)

Pronunciation

  • IPA (Classical): [jaː.nuˈaː.ri.ʊs][1]
  • IPA (Ecclesiastical): [ja.nuˈaː.ri.us][1]

Forms

iānuārius (feminine iānuāria, neuter iānuārium); first/second-declension adjective[1]

Etymology

It is from Iānus “Janus” with the suffix -ārius.[2][1][3] Isidore says the month is named after Janus, or because it is the boundary and door (⟨iānua⟩) of the year.[4]

Earliest recorded meaning

The OLD's earliest citations are from Varro.[2] Köbler's first source is Cicero; he dates Varro 116–27 BC.[5]

Semantic evolution

It meant of or named after Janus, and mēnsis Iānuārius was the month of January, the first of the Roman year after 153 BC, as in Varro.[2]

In Ecclesiastical Latin it was the month of January.[6] Medieval Latin also had a iānuārius “doorkeeper”, from iānua.[7][8] It survives in French janvier, Spanish enero and Portuguese janeiro, and through Old French it gave English January in the late 13th century.[1][3]

Timeline

  • 153 BC – January becomes the first month of the Roman year.[2]
  • 116–27 BC – Varro uses it.[2][5]
  • late 13th century – English January is recorded.[3]

Meanings

Adjective

  1. Of Janus, mēnsis Iānuārius, January.[2]
  2. Of January.[2]

Usage notes

A Medieval Latin iānuārius “doorkeeper” comes from iānua “door”.[7][8]

References

  1. ^ a b c d e Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g Glare, P. G. W., ed. (2012), Oxford Latin Dictionary, 2nd ed., Oxford: Oxford University Press
  3. ^ a b c Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  4. ^ Isidore of Seville, Etymologiarum sive Originum libri XX, ed. W. M. Lindsay (Oxford, 1911).
  5. ^ a b Köbler, Gerhard (2010), Lateinisches Abkunfts- und Wirkungswörterbuch für Altertum und Mittelalter, online ed., koeblergerhard.de
  6. ^ Stelten, Leo F. (1995), Dictionary of Ecclesiastical Latin, Peabody, Mass.: Hendrickson
  7. ^ a b Niermeyer, J. F. (1976), Mediae Latinitatis Lexicon Minus, Leiden: Brill
  8. ^ a b Mittellateinisches Wörterbuch bis zum ausgehenden 13. Jahrhundert (1967–), Munich: C. H. Beck; Bayerische Akademie der Wissenschaften
Cite this entry

“Ianuarius.” Etymologically, 16 Oct. 2026, etymologically.com/la/ianuarius. Accessed 16 Oct. 2026.

Last edited on . ·