Era ['ɪərə]
A series of years beginning from some starting point, which is usually an epoch.
The origin of the word is in some doubt. It has been suggested that it is derived from A ER A, the initial abbreviations of Annus erat Augusti, words employed by the Spaniards to signify the year in which they became subjects of Augustus and adopted the Roman calendar.
The more likely origin, however, is that the word is derived from the Latin aera, plural of aes, which was used to denote brass and was afterwards used to describe counters or items of calculation.
