AAR or Aar may refer to:

Geography

Aar AAR or Aar may refer to: Geography * 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 bas ...

, a river in Switzerland, tributary of the Rhine *

Aar (Lahn) The Aar is a river in western Germany, left tributary of the Lahn. It rises in the Taunus mountains, near Taunusstein. It flows generally north through the towns Taunusstein, Bad Schwalbach, Aarbergen and Hahnstätten. It flows into the Lahn in ...

, a tributary of Lahn river in Germany, descending from the Taunus mountains *

Aar (Dill) Aar is a river of Hesse, Germany. It flows for into the Dill near Herborn. Tributaries The tributaries of the Aar are as follows: *Brühlsbach (right) - 3.3 km *Stadterbach (left) - 6.6 km *Wilsbach (right) - 6.3 km *Weidbach (right) - 5.9 ...

, a tributary of Dill river in Germany, also in the basin of the Lahn *

Aar (Ill) The Aar is a river in the administrative district of Bas-Rhin which crosses the municipalities of Strasbourg and Schiltigheim. It is an arm which separates from the Ill at the University bridge to rejoin it at lock no 51 in Schiltigheim. Togeth ...

, a branch of the Ill river that separates from it in Strasbourg, France and rejoins it further north *

Aar (Twiste) The Twiste is a river of Hesse and of North Rhine-Westphalia, Germany. It is the most important tributary of the Diemel, which it joins in Warburg. Its largest tributaries are the Erpe, Watter, Aar and Wande. See also *List of rivers of Hesse ...

, a tributary of Twiste river in Germany, in the basin of the Weser * Aar (village), a village in Rajasthan, India *

South American–Antarctic Ridge The South American–Antarctic Ridge or simply American-Antarctic Ridge (SAAR or AAR) (in Spanish: Dorsal Antártico-Americana) is the tectonic spreading center between the South American Plate and the Antarctic Plate. It runs along the sea-floo ...

, also known as the American–Antarctic Ridge, a mid-ocean ridge in the South Atlantic *

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest cont ...

, IAAF code AAR

Military

* After-action review, a structured review process used by the U.S. military *

After action report An after action report (or AAR) is any form of retrospective analysis on a given sequence of goal-oriented actions previously undertaken, generally by the author themselves. The two principal forms of AARs are the literary AAR, intended for recrea ...

, a retrospective analysis *

Air-to-air refueling Aerial refueling, also referred to as air refueling, in-flight refueling (IFR), air-to-air refueling (AAR), and tanking, is the process of transferring aviation fuel from one aircraft (the tanker) to another (the receiver) while both aircraft a ...

, the process of transferring aviation fuel from one military aircraft to another during flight * Assistant Automatic Rifleman, a soldier who carries ammunition, see Rifleman#Modern_tactics.

Organizations

All American Racers All American Racers is an American auto racing team and constructor based in Santa Ana, California. Founded by Dan Gurney and Carroll Shelby in 1964, All American Racers initially participated in American sports car and Champ Car races as well a ...

, a former Formula 1 and CART team *

Allens (law firm) Allens is an international commercial law firm that operates in the Asia-Pacific region. The firm is one of the largest in the Asia-Pacific region and has many high-profile political, judicial and corporate alumni. Operations Allens has 149 p ...

, a law firm (formerly known as Allens Arthur Robinson) *

American Academy in Rome The American Academy in Rome is a research and arts institution located on the Gianicolo (Janiculum Hill) in Rome. The academy is a member of the Council of American Overseas Research Centers. History In 1893, a group of American architects, ...

, research and arts institution in Rome *

American Academy of Religion The American Academy of Religion (AAR) is the world's largest association of scholars in the field of religious studies and related topics. It is a nonprofit member association, serving as a professional and learned society for scholars involv ...

, an association of academics who research or teach topics related to religion *

Association for Automated Reasoning The Association for Automated Reasoning (AAR) is a non-profit corporation that serves as an association of researchers working on automated theorem proving, automated reasoning, and related fields. It organizes the CADE and IJCAR conferences and ...

, a non-profit that seeks to advance the field of automated reasoning *

Association of American Railroads The Association of American Railroads (AAR) is an industry trade group representing primarily the major freight Rail transport, railroads of North America (Canada, Mexico and the United States). Amtrak and some regional Commuter rail in North Am ...

, an industry trade group representing the railroads of North America

Transportation

AAR Corporation AAR CORP. is a private provider of aviation services. AAR is headquartered in Wood Dale, Illinois, a Chicago suburb near O'Hare International Airport. The company employs 4,700 people worldwide. History AAR Corp was founded in 1951. I.A. Alle ...

, an American aviation engineering company * AAR coupling, railway coupling specification of the Association of American Railroads *

AAR wheel arrangement The AAR wheel arrangement system is a method of classifying locomotive (or unit) wheel arrangements that was developed by the Association of American Railroads. Essentially a simplification of the European UIC classification, it is widely used ...

, Association of American Railroads system for describing wheel arrangement of locomotives *

All-American Road A National Scenic Byway is a road recognized by the United States Department of Transportation for one or more of six "intrinsic qualities": archeological, cultural, historic, natural, recreational, and scenic. The program was established by Co ...

, a designation for some national scenic byways in the United States *

Ann Arbor Railroad (disambiguation) Ann Arbor Railroad may refer to: *Ann Arbor Railroad (1895–1976) The Ann Arbor Railroad was an American railroad that operated between Toledo, Ohio, and Elberta and Frankfort, Michigan (about 294 route miles) with train ferry operations acr ...

*IATA airport code for

Aarhus Airport Aarhus Airport is a civilian airport located northeast of Aarhus, Denmark. History The airfield was established in 1943 by German occupying forces in World War II and was later used as a Cold War military base for the Danish and other alli ...

in Tirstrup, Denmark *ICAO airline code for

Asiana Airlines Asiana Airlines Inc. ( ) is a South Korean airline headquartered in Seoul.Home
." Asiana Airlines. Retrieved 13 September 2 ...

of South Korea

Other uses

Aar (Star Wars) ''The Han Solo Trilogy'' is a trilogy of now non-canon ('Legends') science-fiction novels set in the '' Star Wars'' galaxy. It follows Han Solo's origins and life before the events depicted in the original ''Star Wars'' trilogy (1977–1983). T ...

, fictional planet in ''Star Wars'' universe *Aar, a fictional planet of the star Deneb, in the "

Captain Future Captain Future is a Pulp magazine, pulp science fiction hero — a space-traveling scientist and adventurer —originally published in Captain Future (magazine), his namesake pulp magazine from 1940 to 1944. The character was created by editors M ...

" stories *

The All-American Rejects The All-American Rejects is an American rock band from Stillwater, Oklahoma, formed in 1999.Air America Radio Air America (formerly Air America Radio and Air America Media) was an American radio network specializing in progressive talk radio. It was on the air from March 2004 to January 2010. The network was founded as a left wing alternative to counter ...

, a domestic United States radio network *

Average accounting return The average accounting return (AAR) is the average project earnings after taxes and depreciation, divided by the average book value of the investment during its life. Approach to making capital budgeting decisions involves the average accounting ret ...

, a capital budgeting investment rule *

Adam's apple reduction Chondrolaryngoplasty (commonly called tracheal shave) is a surgical procedure in which the thyroid cartilage is reduced in size by shaving down the cartilage through an incision in the throat, generally to aid those who are uncomfortable with the g ...

, a surgery *

Afar language The Afar language ( aa, Qafaraf, links=no; also known as ’Afar Af, Afaraf, Qafar af) is an Afroasiatic language belonging to the Cushitic branch. It is spoken by the Afar people inhabiting Djibouti, Eritrea and Ethiopia. Classification Afa ...

(ISO 639 language identification code) *''

African American Review ''African American Review'' (''AAR'') is a scholarly aggregation of essays on African-American literature, theatre, film, the visual arts, and culture; interviews; poetry; fiction; and book reviews. The journal has featured writers and cultural c ...

'', a journal *

Amino acid response Amino acid response is the mechanism triggered in mammalian cells by amino acid starvation. The amino acid response pathway is triggered by shortage of any essential amino acid, and results in an increase in activating transcription factor ATF4, w ...

, the biochemical response of a mammalian cell starved of amino acids *"At any rate", see List of SMS abbreviations *

Alkali–aggregate reaction Surface of a concrete pillar with crack pattern of alkali–silica reaction Alkali–aggregate reaction is a term mainly referring to a reaction which occurs over time in concrete between the highly alkaline cement paste and non-crystalline sili ...

, a chemical reaction leading to expansion in concrete