IR or Ir may refer to:

Arts and media

  • Ir (newspaper), Latvian weekly newspaper
  • Imperator: Rome, a 2019 video game published by Paradox Interactive
  • Integrated resort, a euphemism for a casino in Singapore
  • International Relations (journal), an academic journal
  • I.R. Baboon, a fictional character in the cartoon series I Am Weasel

Businesses and organizations

Transportation

  • Iarnród Éireann (Irish Rail), national passenger and freight railway system of the Republic of Ireland
  • Illinois Railway, US
  • Indian Railways, state-owned railway company of India
  • InterRegio, part of Swiss Federal Railways
  • IR Ishikawa Railway, local railway company in Ishikawa, Japan
  • Iran Air (IATA airline code IR)
  • Israel Railways, state-owned railway company of Israel

Other businesses and organizations

  • Ingersoll Rand (NYSE trading symbol IR)
  • International Rectifier, a former manufacturer of power semiconductors
  • Independent-Republican Party of Minnesota, former name of the Republican Party of Minnesota

Finance

  • Incidence rate (market research)
  • Interest rate, or (when referring to an asset class) interest rate derivative
  • Information ratio, when referring to risk-adjusted returns of a financial security
  • Investor relations, a management responsibility in which companies disclose information for regulatory compliance and for bond/share-holders to make investment judgments

Language

  • Ir (cuneiform), a sign in cuneiform writing
  • Ir language, also known as Ta'Oi language, spoken in parts of Laos and Vietnam
  • Istro-Romanian language

Places

  • Indian Reserve, a section of land in Canada that is controlled by an Indigenous band government
  • Iran, by ISO country code

Science and technology

Biology and medicine

  • Immediate-release, related to time release technology in pharmaceuticals
  • Incidence Rate, in epidemiology
  • Insulin receptor, a transmembrane receptor that is activated by insulin
  • Insulin resistance, a pathological condition
  • Interventional radiology and interventional radiologist, an independent medical specialty
  • Inverted repeat, a sequence of nucleotides that is the reversed complement of another sequence further downstream

Computing

  • .ir, the Internet country code top-level domain for Iran
  • Adobe ImageReady, a bitmap graphics editor shipped with Adobe Photoshop by Adobe Systems
  • Image retention, the LCD and plasma display equivalent of screen burn
  • Information retrieval, the science of searching for information in or as documents or databases
  • Information revolution, one of the theoretical frameworks within which trends in current society can be conceptualized
  • Institutional repository, a digital collection for preserving the intellectual output of an institution
  • Institutional research, the collection, analysis, and reporting of institutional data
  • Instruction register, part of a CPU's control unit
  • Intermediate representation, a computer data structure
  • Internal router

Other uses in science and technology

  • Imaginary numbers, in mathematics, denoted <math>\text{i}\mathbb{R}</math> or
  • Infrared, a portion of the electromagnetic radiation spectrum
  • Impulse response, an output function of a dynamic system presented with a brief input signal
  • Insulation resistance, a measure of insulation material performance
  • Ionizing radiation
  • Iridium, symbol Ir, a chemical element

Other uses

  • Imperial–royal, abbreviation applied to institutions of the Austrian Empire
  • Industrial relations, relations between management and workers in industry
  • Ingenieur, abbreviated ir., an engineer's degree awarded by technical universities in the Netherlands, Belgium, Indonesia, and Malaysia
  • Injured reserve list, a list of professional sports players who are injured and unable to play for an extended time
  • International relations, in political science, the study of foreign affairs of and relations among states
  • International rules football a hybrid code of football

See also

  • <math>\mathbb{R}</math>, the symbol of the set of real numbers in mathematics
  • Inland Revenue Department (disambiguation), a government revenue service in several countries
  • International Rescue (disambiguation)
  • IRS (disambiguation)