eraera

Era comes from Late Latin aera ‘era, epoch’, probably a special use of aera ‘counters’, plural of aes ‘money, brass’.

1. Proto-Indo-Europeanc. 4500–2500 BCE*h₂ey-¹‘to burn’uncertain
2. Proto-Indo-Europeanc. 4500–2500 BCE*h₂éyos²‘metal, copper, bronze’uncertain
3. Proto-Italicc. 1500–700 BCE*aos²‘bronze, copper’uncertain
4. Latinc. 75 BCE–200 CEaes³‘piece of metal, money, brass’uncertain
5. Late Latinc. 200–600 CEaera⁴‘era, epoch’plural of aes
6. Englishearliest quotation 1963era⁴

1. ¹ Wiktionary, Proto-Indo-European *h₂éyos, which cites Martirosyan
2. ² Wiktionary, Latin aes, which cites Ringe
3. ³ Wiktionary, Latin aera
4. ⁴ Wiktionary, English era
5. Earliest quotation in Wiktionary’s entry: 1963, Margery Allingham, London: Chatto & Windus: “Even in an era when individuality in dress is…”.