era

noun

• a long and distinct period of history:his death marked the end of an era leading photographers of the Victorian era
• a system of chronology dating from a particular event:the dawn of the Christian era
• Geology a major division of time that is a subdivision of an aeon and is itself subdivided into periods:the Mesozoic era
• archaic a date or event marking the beginning of a new and distinct period of time: the landing of this English governor was an era in their lives