Etymologically

aera

Etymology and origin of the Latin word aera

Confidence
Probable
Formation
Derivation
First attested
Rufius Festus
Ultimate origin
Latin (aes)
Etymology tree
inherited borrowed derived
Latin aera
English era

Pronunciation

  • IPA (Classical): [ˈae̯.ra][1]
  • IPA (Ecclesiastical): [ˈɛː.ra][1]

Forms

aera f (genitive aerae); first declension[1]

Etymology

It is post-classical, probably a special use of aera “counters”, the plural of aes “bronze, money”, made into a feminine singular.[1][2][3] The TLL calls it a plural of aes with changed declension and gender.[3]

Earliest recorded meaning

Rufius Festus, in his Breviarium in the late 4th century, uses it of a number or item in a reckoning.[4][5]

Semantic evolution

Its first sense was a number used in a calculation, an item of an account.[6][5] From that it came to mean the date from which years are counted, an era: Isidore of Seville says the era of each year was fixed by Caesar Augustus at the first census of the Roman world.[7][4] The Spanish era began in 38 BC, and Etymonline dates this use to the 7th century.[2]

In medieval Latin it was also the number of a chapter or section, especially in laws and canon collections.[8][9] English era is recorded as aera in the 1610s and as era in 1716.[2]

Timeline

  • late 4th century AD – Rufius Festus uses it of a number.[4]
  • c. 560–636 AD – Isidore of Seville explains the era as fixed by Augustus.[7][10]
  • 1610s – English aera is recorded, later era.[2]

Meanings

Noun

  1. (Late Latin) A number, an item of an account.[6][5]
  2. (Late Latin) An era, the epoch from which years are counted.[1][6]
  3. (Medieval Latin) The number of a chapter or section.[8][9]

Word family

  • aerinus

Usage notes

A different word is aera “darnel”, a weed among grain, borrowed from Greek and used by Pliny the Elder.[11][5]

References

  1. ^ a b c d e Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  3. ^ a b Thesaurus linguae Latinae (1900–), Leipzig: Teubner; Berlin: De Gruyter; open-access ed., Munich: Bayerische Akademie der Wissenschaften
  4. ^ a b c Gaffiot, Félix (2016), Dictionnaire latin-français, new ed. by Gérard Gréco et al. (Gaffiot 2016), online ed.
  5. ^ a b c d Georges, Karl Ernst (1913–1918), Ausführliches lateinisch-deutsches Handwörterbuch, 8th ed., ed. Heinrich Georges, Hannover; Leipzig: Hahn
  6. ^ a b c Lewis, Charlton T.; Short, Charles (1879), A Latin Dictionary, Oxford: Clarendon Press
  7. ^ a b Isidore of Seville, Etymologiarum sive Originum libri XX, ed. W. M. Lindsay (Oxford, 1911).
  8. ^ a b Niermeyer, J. F. (1976), Mediae Latinitatis Lexicon Minus, Leiden: Brill
  9. ^ a b Mittellateinisches Wörterbuch bis zum ausgehenden 13. Jahrhundert (1967–), Munich: C. H. Beck; Bayerische Akademie der Wissenschaften
  10. ^ Köbler, Gerhard (2010), Lateinisches Abkunfts- und Wirkungswörterbuch für Altertum und Mittelalter, online ed., koeblergerhard.de
  11. ^ Glare, P. G. W., ed. (2012), Oxford Latin Dictionary, 2nd ed., Oxford: Oxford University Press

Borrowed into

Cite this entry

“Aera.” Etymologically, 15 Oct. 2026, etymologically.com/la/aera. Accessed 16 Oct. 2026.

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