era

noun

1. a system of reckoning time by numbering the years from some important occurrence or given point of time: the Christian Era
2. an event or date that marks the beginning of a new or important period in the history of something
3. a period of time measured from some important occurrence or date
4. a period of time considered in terms of noteworthy and characteristic events, developments, individuals, etc.: an era of progress
5. Geol. a subdivision of an eon

1. Baseball earned run average
   also era
2. Equal Rights Amendment