(baseball) Initialism of earned run average, a baseball statistic. / (electronics) Initialism of electrically reconfigurable array. / (military) Initialism of explosive reactive armor.

(US) Initialism of Equal Rights Amendment. / (EU, railways) Initialism of European Railway Agency (called today the European Union Agency for Railways)

A time period of indeterminate length, generally more than one year. / (geology) A geochronologic unit of tens to hundreds of millions of years; a subdivision of an eon, and subdivided into periods.

plural of era

plural of ERA

(chronology) The secular equivalent of anno Domini and the Christian Era, the internationally recognized method of numbering years on the Gregorian calendar.

plural of geologic era

(geology, Paleontology) A subdivision of geologic time that divides an eon into smaller timeframes.

The current date era beginning approximately 2000 years ago in the Gregorian calendar, based on the (assumed) birth of Jesus Christ.

Any of several periods of history noted for a particular style of art, architecture, literature or music termed classical