AR

AR, Ar or ar may refer to:

• The letter R

Places

• Ar (city), ancient Moab
• .ar, the ccTLD for Argentina
• Appenzell Outer Rhodes, Switzerland
• Arad County, Romania
• Argentina (ISO 3166-1 alpha-2 country code)
• Arkansas, a state in the United States whose postal abbreviation is "AR"
• Arunachal Pradesh, a state in north-eastern India
• Province of Arezzo, Italy

People

• A.R Rahman, Indian singer and music composer

Art, entertainment, and media

Art

• a.r. group, Polish artists and poets, including Katarzyna Kobro and Julian Przyboś

Fictional entities

• Ar, largest city on the fictional planet Gor, in the novel series by John Norman
• Alternate Reality, a primary racial trait in the 4X strategy computer game Stars!
• Arlesdale Railway, a fictional railway in the Railway Series by W.V. Awdry
• Armaan and Riddhima, two lovebirds of the youthful show Dill Mill Gayye

Games

• Air Rivals, a MMORPG/FPS game, the new Space Cowboy
• Armadillo Run, a physics-based, independently developed computer game

Literature

• Alex Rider, a fictional character and book series by author Anthony Horowitz
• Alternate reality (disambiguation), fictional concept

Music

Entities

• Abbey Road Studios, a recording studio
• Artists and repertoire or A&R, the division of a record label or music publishing company responsible for talent scouting and overseeing the artistic development of recording artists and/or songwriters
• Atlantic Records

Albums

• Abbey Road, the eleventh album by The Beatles

Periodicals

• Absolute Return + Alpha, a hedge fund publication
• American Renaissance (magazine), a white nationalist magazine and website
• Architectural Review, a publication of contemporary architecture
• Arizona Republic, a newspaper published in Phoenix, Arizona
• Armeerundschau, a magazine of the East German army

Computing and technology

• ar (Unix), a Unix archive format and handling tool
• Abandonia Reloaded, a freeware games web community
• Accelerated Reader, educational reading assessment software
• Action Replay, video game device
• Active record pattern
• Activation record, a computer science term for the set of data regarding an active subroutine, stored within the stack
• Aspect ratio (image), The relationship between the width and height of an image
• Augmented reality, an application of virtual reality in the real world

Military

• AR, the United States Navy hull classification symbol for "repair ship"
• Army Reserve (Ireland), the land component of the Irish Reserve Defence Forces (RDF)
• Army Ranger Wing also called Army Rangers, Irish military special operations forces

Science and mathematics

• ar (function prefix) (area), prefix of inverse hyperbolic functions
• Adrenergic Receptor, a class of G protein-coupled receptors
• Adverse reaction, in pharmacy
• Androgen receptor, a nuclear hormone receptor
• Anti-reflective coating, a coating on lenses that allows better light transmission through the lens
• Aortic Regurgitation, a heart valve disease
• Archimedes number, in physics and engineering
• Argent, the heraldic tincture of silver
• Argon, chemical symbol
• Artificial respiration, any means of assisting or stimulating respiration
• Aryl, functional group
• Astronomer Royal, post in the Royal Households of the United Kingdom
• Atomic Radius
• Autoregressive model, concerning random processes in statistics
• Autosomal Recessive
• Analytical Reagent, a higher purity than SLR (Standard Laboratory Reagent)
• AR, silver in numismatics
• Relative atomic mass

Social sciences

• Accelerated Rehabilitative Disposition
• American Revolution

Transportation

• Aerolíneas Argentinas (IATA code)
• Alfa Romeo, automobile

Other uses

• A & R Sales, a defunct firearms manufacturer
• "Ar" or "argh", a word in the West Country dialect of English, generally indicating agreement or assent and commonly associated with pirates
• AR or ᛅ, rune of the Younger Futhark
• Ar., an abbreviation related to Kodashim
• Ar. also used for salutation for Professional Architect
• AR-15, a rifle
• Accounts Receivable, an accounting
• Animal rights
• Arabic language (ISO 639 alpha-2 language code)
• Aspect ratio (wing), the relationship between the length and breadth (chord) of a wing
• Assistant referee (association football)
• Avis de réception (English: Advice or acknowledgment of receipt), a postal service
• Age regression (disambiguation), various meanings