title: ER
text: # ER
  
  ER or Er may refer to:
  
  ## Places
  
  * English Republic, alternative name for the Commonwealth of England
  * Eritrea (ISO 3166-2 two letter country code)
  
  ### United States
  
  * East Rochester, New York
  * Erie, Pennsylvania
  
  ## People
  
  * Er (biblical person), the eldest son of Judah in the biblical book of Genesis
  * Nie Er (1912–1935), Chinese composer
  * Elliot Rodger (July 24, 1991 – May 23, 2014), English-American incel mass shooter
  * A Royal cypher representing a monarch
     * Elizabeth Regina (ER), the royal cypher of Elizabeth I
     * Edward Rex (ER / EVIIR), the royal cypher of Edward VII
     * Edward Rex (ER / EVIIIR), the royal cypher of Edward VIII
     * Elizabeth II Regina (EIIR), the royal cypher of Elizabeth II
  
  ### Fictional characters
  
  * Er, a character in Plato's Myth of Er
  
  ## Arts, entertainment and media
  
  ### Music
  
  * Er, an album by Nils Petter Molvær
  * "ER" (song), a 2012 single by Japanese boy band Kanjani Eight
  * "ER", a song by Royce da 5'9" featuring Kid Vishis from Success Is Certain
  
  ### Periodicals
  
  * Chico Enterprise-Record, the daily newspaper of Chico, California
  
  ### Television
  
  * ER (TV series), a 1994–2009 American television medical drama series
  * E/R, a 1984–1985 American television sitcom
  
  ## Businesses and organizations
  
  * Astar Air Cargo (IATA designator ER)
  * Eastern Railway (India)
  * Eldorado Reno, a hotel and casino in Reno, Nevada
  * Eldorado Resorts, a gaming company located in Reno, Nevada
  * Entre Ríos Railway in Argentina (reporting mark ER)
  * Estonian Reform Party
  * United Russia, or Yedinaya Rossiya, a Russian political party
  
  ## Finance and banking
  
  * ER, abbreviation of exchange rate
  * ER, abbreviation of expense ratio
  
  ## Language
  
  * Er (Cyrillic) (Р / р), a letter of the Cyrillic alphabet corresponding to the Latin letter "R"
  * Er (cuneiform), a sign in cuneiform writing
  * "er", a filler word in English
  * Er, alternate spelling for Yer (Ъ / ъ), the hard-sign letter of the Cyrillic alphabet
  * Suffix -er
     * -er, a suffix added to adjectives or adverbs to form a comparative (e.g., fast to faster)
     * -er, a suffix added to a noun to indicate resident of, as in New Yorker
     * -er, a suffix added to a verb to make it an agent noun (e.g., cut to cutter)
     * Oxford "-er", a suffix used to form words like rugger and footer
     * Erhua (儿化), rhotacization of spoken syllables in Beijing dialect of Mandarin Chinese with the -er suffix (儿)
  
  ## Science and technology
  
  * Erdős–Rényi model, a model in graph theory
  
  ### Biology and medicine
  
  * Emergency room, or emergency department, in a medical facility
  * Endoplasmic reticulum, a type of organelle in cell biology
  * Er blood group system
  * Equine exertional rhabdomyolysis, a syndrome that damages muscle tissue in horses
  * Estrogen receptor, a type of protein molecule
  * Extraction ratio, a pharmacokinetic property
  
  ### Chemistry and physics
  
  * $\epsilon _{r}$, a representation for relative static permittivity
  * Electrorheological (ER) fluid, a type of chemical suspension
  * Enantiomeric ratio, a concept in chemistry
  * Erbium, symbol Er, a chemical element
  * Einstein-Rosen bridge (ER) relativistic wormholes
  
  ### Computing
  
  * .er, country code top-level domain (ccTLD) for Eritrea
  * Entity–relationship model, a conceptual representation of data
  * Error Resilience, an audio coding method used in MPEG-4 Part 3
  
  ## Other uses
  
  * Er., Hebrew abbreviation for 'Eruvin, the second tractate of Moed
  * Earned run, a term in the game of baseball
  * Emergency Response, incident response team or emergency procedure related to emergency services
  * English Reports of the English Courts from 1220 to 1866
  