AAR

AAR or Aar may refer to:

Aviation

• AAR Corporation, an American aviation engineering company
• "Air-to-air refueling", also known as aerial refueling, the practice of transferring fuel from one aircraft to another during flight
• AAR, IATA airport code for Aarhus Airport in Tirstrup, Denmark
• AAR, ICAO airline code for Asiana Airlines of South Korea

Finance

• Average accounting return, a capital budgeting investment rule

Medicine

• Adam's apple reduction, a surgery

Military

• After action review, a structured review process used by the U.S. military
• After action report, military terminology

Music

• The All-American Rejects, an American rock band

Organizations

• All American Racers, a former Formula 1 and CART team
• All-American Rejects, a 2000s American rock band
• Allens, a law firm (formerly known as Allens Arthur Robinson)
• American Academy of Religion, an association of academics who research or teach topics related to religion
• Association for Automated Reasoning, a non-profit that seeks to advance the field of automated reasoning
• Association of American Railroads, an industry trade group representing the railroads of North America
  • AAR wheel arrangement, their system for describing wheel arrangement of locomotives
• Arizona Association Realtors, a group representing the Real Estate brokers in the state of Arizona

Rivers

• Aar, a river in Switzerland, tributary of the Rhine
• Aar (Lahn), a tributary of Lahn river in Germany, descending from the Taunus mountains
• Aar (Dill), a tributary of Dill river in Germany, also in the basin of the Lahn
• Aar (Twiste), a tributary of Dill river in Germany, in the basin of the Weser

Television and radio

• Air America Radio, a domestic United States radio network

Other uses

• Aar (Star Wars), fictional planet in Star Wars universe
• Afar language (ISO 639 language identification code)
• All-American Road, a designation for some national scenic byways in the United States
• Ann Arbor Railroad (disambiguation)
• AAR coupling
• "At any rate": see List of SMS abbreviations
• Amino acid response, the biochemical response of a mammalian cell starved of amino acids
• Aar, a fictional planet of the star Deneb, in the "Captain Future" stories
• Accumulation Area Ratio, the percentage of a glacier that is a snow-covered accumulation zone at the end of the summer melt season
• Ahr, a river in Germany, tributary of the Rhine
• Aare (disambiguation)
• South American–Antarctic Ridge, also known as the American–Antarctic Ridge, a mid-ocean ridge in the South Atlantic