AR

Music • Artists and repertoire • AR (EP), the debut EP by Addison Rae Periodicals • Absolute Return + Alpha, a hedge fund publication • The Adelaide Review, an Australian arts magazine • American Renaissance (magazine), a white nationalist magazine and website • Architectural Review, a British architectural journal • Armeerundschau, a magazine of the East German army Other media • Ar, city on the fictional planet Gor • A.r. group, an avant-garde art group ==Business==

• Accounts receivable, abbreviated as AR or A/R • Acoustic Research, an American audio electronics manufacturer • Aerojet Rocketdyne, an American aerospace and defense manufacturer • Aerolíneas Argentinas (IATA airline code AR) • AtkinsRéalis, Canadian engineering company • Some Alfa Romeo car models, e.g. AR51 • Toyota AR engine ==Language==

• Ar, the Latin letter R when spelled out • Ar (cuneiform), a cuneiform combined sign • Arabic, by ISO 639-1 language code ==Science and technology==

Computing • Accelerated Reader, educational reading assessment software • Adaptive routing, in networking • Adobe Aero, an Adobe software • ar (Unix), a Unix archive format and handling tool • Augmented reality, a type of 3D human-computer interaction similar to virtual reality Biology and medicine • Androgen receptor, a nuclear hormone receptor • Aortic regurgitation, a heart valve disease • Autosomal recessive inheritance Mathematics • ar-, a prefix of inverse hyperbolic functions • Autoregressive model, concerning random processes in statistics Physics, chemistry and engineering • Aqua regia, a chemical mixture • Archimedes number in fluid dynamics • Argon (Ar), a chemical element • Aryl group, in organic chemistry • Aspect ratio (aeronautics), of a wing • Relative atomic mass (Ar), the ratio of the average mass of atoms of an element • Anti-reflective coating ==Military and weapons==

• A US Navy hull classification symbol: Repair ship (AR) • Armalite Rifle • AR-15–style rifle, rifles based on ArmaLite's AR-15 • Army Reserve (Ireland), the land component of the Irish Reserve Defence Forces (RDF) ==Places==

• Ar (city), in ancient Moab • Appenzell Ausserrhoden, Switzerland • Province of Arezzo, Italy, vehicle registration code • Argentina (ISO 3166-1 alpha-2 country code) • .ar, the country code Top Level Domain for Argentina • Arkansas, United States • Armstrong–Ringsted Community School District, Iowa, United States • Arunachal Pradesh, a state of India ==Politics and ethics==

• Affirmative Repositioning, a political movement in Namibia • Animal rights, a philosophy • Animal rights movement, a social movement advocating for other animals • Antipodean Resistance, an Australian neo-Nazi group ==Other uses==

• Alternate reality (disambiguation), includes various concepts • 🜇 or AR, a numismatic abbreviation for "silver" • Argent, the heraldic tincture of silver • Assistant referee (association football) • Auto rickshaw, a motorized three-wheeled vehicle common in South Asia • Avis de réception, postal advice or acknowledgement of receipt == See also ==