The Meaning of Era: What It Is and How To Use It

Do you know the definition of era? This article will provide you with all of the information you need on the word era, including its definition, etymology, usage, examples, and more!

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What does the word era mean?

According to the Merriam-Webster Unabridged Dictionary of the English Language, American Heritage, and Collins English Dictionary, the word era is a noun that refers to a fixed point in time from which a series of years is reckoned, or some memorable date or event that begins a new period in the history of a person or thing. This is also used as a system of chronological notation such as a period identified by a figure or feature, a stage in development, or the major division of geologic time shorter than epochs or an eon, which is the longest division of geologic time. For example, Christians have their own Christian era that refers to the period of time before Christ (B.C) and anno domini (A.D.). Most people use Before Common Era (B.C.E.) and Common Era (C.E.).

An era might be determined by a distinctive character, like the era of Henry VIII. It could refer to a point in time that is the beginning of any distinctive period or given date, or the beginning of a new system of chronology or extended period of time or point of time due to particular circumstances. The era of modern medicine can be said to start with the important event of the advent of the discovery of antibiotics. The civil rights era is classified by the fight against disctiminaiton. The digital era may be considered as starting in the 80s with the technology boom. An era might begin on a specific date or particular date, or it might be a time period of indeterminate length. The pronunciation of era is ˈɪərə.

According to Britannica, there are ten eras that are recognized by the International Union of Geological Sciences, listed below. There are a number of periods contained within Precambrian time (approximately 4.6 billion to 541 million years ago) are classified independently. The Phanerozoic eon is divided into the three most recent eras.

  •  Eoarchean Era (4.0 billion to 3.6 billion years ago)
  •  Paleoarchean Era (3.6 billion to 3.2 billion years ago)
  •  Mesoarchean Era (3.2 billion to 2.8 billion years ago)
  •  Neoarchean Era (2.8 billion to 2.5 billion years ago)
  •  Paleoproterozoic Era (2.5 billion to 1.6 billion years ago)
  •  Mesoproterozoic Era (1.6 billion to 1.0 billion years ago)
  •  Neoproterozoic Era (1.0 billion to 541 million years ago)
  •  Paleozoic Era (541 million to about 252 million years ago)
  •  Mesozoic Era (roughly 252 million to 66 million years ago)
  •  Cenozoic Era (66 million years ago to the present)

ERA is also an acronym and has many different meanings. Below is a list of possible abbreviation meanings for ERA, from The Free Dictionary. When using these, make sure you provide proper context since there are multiple different definitions of ERA. 

  •  Earned Run Average (baseball, measure of a pitcher’s effectiveness, average number of earned runs)
  •  Equal Rights Amendment
  •  Electronic Research Administration
  •  Electronic Retailing Association
  •  Equal Rights Advocates
  •  Ecological Risk Assessment
  •  Energy Resources of Australia
  •  European Research Area
  •  Educational Research Association (various locations)
  •  Electronics Representatives Association
  •  Environmental Risk Assessment
  •  Electronic Remittance Advice (health insurance)
  •  Electronic Records Archive (NARA)
  •  European Renal Association
  •  ESET Remote Administrator (software)
  •  Excellence in Research for Australia
  •  Expense Reduction Analysts
  •  Extended Range Artillery
  •  Effective Resource Allocation
  •  European Railway Agency
  •  Emerging Research Area
  •  Early Rheumatoid Arthritis
  •  Explosive Reactive Armor
  •  Employment Relations Act (various organizations)
  •  Edinburgh Research Archive (Scotland, UK)
  •  Economic Research Analysis
  •  Enterprise Reference Architecture (software)
  •  Environment Related Activities
  •  Education Reform Act (1998)
  •  Evoked Response Audiometry
  •  Europäische Rechtsakademie Trier (German: Academy of European Law Trier; Trier, Germany)
  •  European Robotic Arm
  •  European Regions Airline Association
  •  En-Route Alternate (aviation)
  •  European Rotogravure Association
  •  Environmentally Relevant Activity
  •  Educational Research Abstracts
  •  English Racing Automobiles
  •  Entity Relation Attribute
  •  Embedded Remote Access
  •  Ethics Risk Assessment (software)
  •  Electronic Research Announcements (journal)
  •  Estonian Road Administration
  •  Elderly Rental Assistance (Oregon)
  •  Entity Relationship Attribute (model)
  •  Economics Research Associates (California)
  •  Engineering Research Associates
  •  Economic Regulation Authority (Australia)
  •  European Ramblers Association
  •  Expedited Response Action
  •  European Regional Airlines Association
  •  Extended Range Ammunition
  •  Emergency Roadside Assistance
  •  Energy Reorganization Act of 1974
  •  Electrical Response Audiometry
  •  Esperanto Radikala Asocio (Italian)
  •  Early Retirement Age (pension benefit calculations)
  •  Electronic Realty Associates
  •  European Recovery Act
  •  English Racing Automobiles (UK)
  •  European Radon Association
  •  Embedded Remote Access (Dell Computer Corporation)
  •  Engine Room Artificer (Royal Navy)
  •  Economic Regulatory Administration
  •  Excitatory Response Area
  •  Environnement-Recherche-Action (French: Environment-Action Research; Cameroon)
  •  Electrical Research Association (UK)
  •  Education Recording Agency (licensing scheme; intellectual property; UK)
  •  Environmental Restoration Account (cleanup funds)
  •  Employee Reimbursement Account
  •  Eigensystem Realization Algorithm
  •  European Radio Awards
  •  Energy Research Abstracts
  •  Études & Recherches en Archéologie (French: Studies & Research in Archaeology)
  •  Environnement de Réseaux Autonomes (French: Autonomous Networks Environment)
  •  Elder Rights Association (various locations)
  •  Endothelin-Receptor Agonist (hypertension treatment)
  •  Economic Regulatory Agency
  •  Extended Registry Attribute
  •  Environmental Research Applications
  •  Exabiology and Radiation Assembly (European Space Agency experiment)
  •  Entity-Relationship Analysis
  •  Electric Railroaders’ Association, Inc
  •  Electronics Recycling Association (Canada)
  •  Economic Recovery Assistance
  •  Endurance Riders of Alberta
  •  Electronic Rothamsted Archive
  •  Electrically Reconfigurable Array
  •  Event Recording Automata
  •  Engine Room Assistant
  •  Everglades Restoration Act
  •  Emergency Reserve Account
  •  Employee Riders Association (of the Harley-Davidson Motor Company)
  •  Estimated Relative Abundances
  •  Egyptians Relief Association (Burke, VA)
  •  English Regional Associations
  •  Executive Recruitment Association
  •  Expedited Removal Action
  •  e-Research Australasia
  •  Extended Range ASROC
  •  Extra Regimental Assignment
  •  Endothelium-Receptor Antagonist
  •  Execution Review Account
  •  Event Relations Analyzer

What is the origin of the word era?

According to Etymonline, the word era comes from the Late Latin aera counters. This is the plural of aes brass which referred to pieces of brass money or bronze coin. This word is of Indo-European roots.

Overall, the word era (pl. eras) means a specific period of time. This can be qualified in many different ways, from a specific date to the circumstances or personages surrounding an era.


  1. era | Definition & Facts | Britannica 
  2. ERA – What does ERA stand for? | The Free Dictionary 
  3. Era | Definition of Era | Merriam-Webster 
  4. era | Origin and meaning of era | Online Etymology Dictionary