ER or Er may refer to:

People

Er (biblical person) :''This article discusses close relatives of Judah (biblical figure), Judah. Er is also a name listed by the Gospel of Luke's version of the genealogy of Jesus''. In the Bible, biblical Book of Genesis, Er ( "watcher"; ) was the eldest son of Juda ...

, 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 In modern heraldry, a royal cypher is a monogram or monogram-like device of a country's reigning Monarch, sovereign, typically consisting of the initials of the monarch's name and title, sometimes interwoven and often surmounted by a Crown (heral ...

representing a monarch ** Elizabeth Regina (ER), the royal cypher of

Elizabeth I Elizabeth I (7 September 153324 March 1603) was List of English monarchs, Queen of England and List of Irish monarchs, Ireland from 17 November 1558 until her death in 1603. She was the last and longest reigning monarch of the House of Tudo ...

** Edward Rex (ER / EVIIR), the royal cypher of

Edward VII Edward VII (Albert Edward; 9 November 1841 – 6 May 1910) was King of the United Kingdom and the British Dominions, and Emperor of India, from 22 January 1901 until Death and state funeral of Edward VII, his death in 1910. The second child ...

** Edward Rex (ER / EVIIIR), the royal cypher of

Edward VIII Edward VIII (Edward Albert Christian George Andrew Patrick David; 23 June 1894 – 28 May 1972), later known as the Duke of Windsor, was King of the United Kingdom and the Dominions of the British Empire, and Emperor of India, from 20 January ...

** Elizabeth II Regina (EIIR), the royal cypher of

Elizabeth II Elizabeth II (Elizabeth Alexandra Mary; 21 April 19268 September 2022) was Queen of the United Kingdom and other Commonwealth realms from 6 February 1952 until Death and state funeral of Elizabeth II, her death in 2022. ...

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 ''Success Is Certain'' is the fifth studio album by rapper Royce da 5'9" released on August 9, 2011. The first single is "Writer's Block" featuring Eminem, which was released in March 2011. Production for the album came from DJ Premier, Mr. Po ...

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) * Entre Ríos Railway in Argentina (reporting mark ER) *

Estonian Reform Party The Estonian Reform Party () is a liberal political party in Estonia. The party has been led by Kristen Michal since 2024. It is colloquially known as the "Squirrel Party" () or as "the Squirrels" (), referencing its logo. It was founded in ...

Finance and banking

* ER, abbreviation of

exchange rate In finance, an exchange rate is the rate at which one currency will be exchanged for another currency. Currencies are most commonly national currencies, but may be sub-national as in the case of Hong Kong or supra-national as in the case of ...

* ER, abbreviation of

expense ratio The expense ratio of a stock or asset fund is the total percentage of fund assets used for administrative, management, advertising (12b-1), and all other expenses. An expense ratio of 1% per annum means that each year 1% of the fund's total assets ...

Language

Er (Cyrillic) Er (Р р; italics: ) is a letter of the Cyrillic script. It commonly represents the alveolar trill , like the "rolled" sound in the Scottish pronunciation of in "curd". History The Cyrillic letter Er was derived from the Greek lette ...

(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 The degrees of comparison of adjectives and adverbs are the various forms taken by adjectives and adverbs when used to compare two entities (comparative degree), three or more entities (superlative degree), or when not comparing entities (positi ...

(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 In linguistics, an agent noun (in Latin, ) is a word that is derived from another word denoting an action, and that identifies an entity that does that action. For example, ''driver'' is an agent noun formed from the verb ''drive''. Usually, '' ...

(e.g., ''cut'' to ''cutter'') **

Oxford "-er" The Oxford "-er", or often "-ers", is a colloquial and sometimes facetious suffix prevalent at Oxford University from about 1875, which is thought to have been borrowed from the slang of Rugby School. The term was defined by the lexicographer ...

, a suffix used to form words like ''rugger'' and ''footer'' **

Erhua ''Erhua'' (), also called "erization" or "rhotacization of syllable finals", is a phonological process that adds r-coloring or the ''er'' (; ) sound to syllables in spoken Mandarin Chinese. ''Erhuayin'' () is the pronunciation of "er" after r ...

(儿化), rhotacization of spoken syllables in

Beijing dialect The Beijing dialect ( zh, s=北京话, t=北京話, p=Běijīnghuà), also known as Pekingese and Beijingese, is the prestige dialect of Mandarin spoken in the urban area of Beijing, China. It is the phonological basis of Standard Chinese, the ...

Mandarin Chinese Mandarin ( ; zh, s=, t=, p=Guānhuà, l=Mandarin (bureaucrat), officials' speech) is the largest branch of the Sinitic languages. Mandarin varieties are spoken by 70 percent of all Chinese speakers over a large geographical area that stretch ...

with the -er suffix (儿)

Science and technology

Biology and medicine

Emergency room An emergency department (ED), also known as an accident and emergency department (A&E), emergency room (ER), emergency ward (EW) or casualty department, is a medical treatment facility specializing in emergency medicine, the acute care of pat ...

, or emergency department, in a medical facility *

Endoplasmic reticulum The endoplasmic reticulum (ER) is a part of a transportation system of the eukaryote, eukaryotic cell, and has many other important functions such as protein folding. The word endoplasmic means "within the cytoplasm", and reticulum is Latin for ...

, a type of organelle in cell biology * Er blood group system * Equine exertional rhabdomyolysis, a syndrome that damages muscle tissue in horses *

Estrogen receptor Estrogen receptors (ERs) are proteins found in cell (biology), cells that function as receptor (biochemistry), receptors for the hormone estrogen (17β-estradiol). There are two main classes of ERs. The first includes the intracellular estrogen ...

, a type of protein molecule * Extraction ratio, a pharmacokinetic property

Chemistry and physics

\epsilon_r

, a representation for

relative static permittivity The relative permittivity (in older texts, dielectric constant) is the permittivity of a material expressed as a ratio with the electric permittivity of a vacuum. A dielectric is an insulating material, and the dielectric constant of an insula ...

* Electrorheological (ER) fluid, a type of chemical suspension * Enantiomeric ratio, a concept in chemistry *

Erbium Erbium is a chemical element; it has Symbol (chemistry), symbol Er and atomic number 68. A silvery-white solid metal when artificially isolated, natural erbium is always found in chemical combination with other elements. It is a lanthanide, a rare- ...

, symbol Er, a chemical element * Einstein-Rosen bridge (ER) relativistic wormholes

Computing

* .er, country code top-level domain (ccTLD) for Eritrea *

Entity–relationship model An entity–relationship model (or ER model) describes interrelated things of interest in a specific domain of knowledge. A basic ER model is composed of entity types (which classify the things of interest) and specifies relationships that can e ...

, a conceptual representation of data * Error Resilience, an audio coding method used in

MPEG-4 Part 3 MPEG-4 Part 3 or MPEG-4 Audio (formally ISO/ IEC 14496-3) is the third part of the ISO/ IEC MPEG-4 international standard developed by Moving Picture Experts Group. It specifies audio coding methods. The first version of ISO/IEC 14496-3 was publis ...

Other uses

Eritrea Eritrea, officially the State of Eritrea, is a country in the Horn of Africa region of East Africa, with its capital and largest city being Asmara. It is bordered by Ethiopia in the Eritrea–Ethiopia border, south, Sudan in the west, and Dj ...

(ISO 3166-2 two letter country code) * Er., Hebrew abbreviation for 'Eruvin, the second tractate of

Moed Moed (, "Festivals") is the second Order of the Mishnah, the first written recording of the Oral Torah of the Jewish people (also the Tosefta and Talmud). Of the six orders of the Mishna, Moed is the third shortest. The order of Moed consists ...

Earned run In baseball, an earned run is any run that was fully enabled by the offensive team's production in the face of competent play from the defensive team. Conversely, an unearned run is a run that would not have been scored without the aid of an erro ...

, 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