A3, A03 or A.III may refer to: *

A3 paper ISO 216 is an international standard for paper sizes, used around the world except in North America and parts of Latin America. The standard defines the "A", "B" and "C" series of paper sizes, including A4, the most commonly available paper siz ...

, a paper size defined by ISO 216

Biology

* A3 regulatory sequence, a sequence for the insulin gene * Adenosine A₃ receptor, a human gene * Annexin A3, a human gene * ATC code A03 ''Drugs for functional gastrointestinal disorders'', a subgroup of the Anatomical Therapeutic Chemical Classification System *

Brachydactyly type A3 Brachydactyly ( Greek βραχύς = "short" plus δάκτυλος = "finger"), is a medical term which literally means "short finger". The shortness is relative to the length of other long bones and other parts of the body. Brachydactyly is an ...

, a disease *

British NVC community A3 (Spirodela polyrhiza - Hydrocharis morsus-ranae community) This article gives an overview of the aquatic communities in the British National Vegetation Classification system. Introduction The aquatic communities of the NVC were described in Volume 4 of '' British Plant Communities'', first published in ...

, a British Isles plants community *

Gibberellin A3 Gibberellins (GAs) are plant hormones that regulate various developmental processes, including stem elongation, germination, dormancy, flowering, flower development, and leaf and fruit senescence. GAs are one of the longest-known classes of p ...

, a plant hormone *

HLA-A3 HLA-A3 (A3) is a human leukocyte antigen ''serotype'' within HLA-A serotype group. The serotype is determined by the antibody recognition of α3 subset of HLA-A α-chains. For A3, the alpha, "A", chain are encoded by the HLA-A allele group and t ...

, a Human MHC Serotype HLA-A * Subfamily A3, a

rhodopsin-like receptors Rhodopsin-like receptors are a family of proteins that comprise the largest group of G protein-coupled receptors. Scope G-protein-coupled receptors, GPCRs, constitute a vast protein family that encompasses a wide range of functions (including ...

subfamily * Urea transporter A3, a trans-membrane protein

Games

* ''

A3! ''A3!'' (acronym for "Act! Addict! Actors!") is a Japanese mobile game developed by Liber Entertainment. The game was released on January 27, 2017, in Japan. It was given a worldwide English release on October 23, 2019, which later ended servi ...

'', a Japanese video game and multimedia franchise *

A3 - Assault on the Aerie of the Slave Lords ''Scourge of the Slave Lords'' (A1–4) is an adventure module for the ''Dungeons & Dragons'' fantasy role-playing game, published by TSR, Inc. in 1986. It combines the contents of four earlier modules, all set in the World of Greyhawk campaign ...

, a 1981 module for the Dungeons & Dragons fantasy role-playing game * Alpha Trion, as the former name of this character from the Transformers Series *

Bird's Opening Bird's Opening (or the Dutch Attack) is a chess opening characterised by the move: :1. f4 Bird's is a standard flank opening. White's strategic ideas involve control of the e5-square, offering good attacking chances at the expense of slightly ...

(A03), in chess, by the Encyclopaedia of Chess Openings code

Music

* A3, a

musical note In music, a note is the representation of a musical sound. Notes can represent the pitch and duration of a sound in musical notation. A note can also represent a pitch class. Notes are the building blocks of much written music: discretizatio ...

, the A below Middle C * Alabama 3, a band known as A3 in the U.S. to avoid confusion with the country group Alabama * A-3, a Yamaha musical instrument product

Sports

A3 (classification) A3 is an amputee sport classification used by the International Sports Organization for the Disabled (ISOD) for people with acquired or congenital amputations. A3 classified sportspeople have both legs amputated below knee. Their amputations imp ...

, an amputee sport classification * A3 Champions Cup, a club football tournament also known as the East Asian Champions Cup *

Arrows A3 The Arrows A3 was a Formula One car which the Arrows team used to compete in the 1980 and 1981 Formula One seasons. After the failure of the A2 in the 1979 Formula One season, the A3 was a very conventional design. The A3 featured a short whee ...

, a 1980 racing car * A3, a

climbing grade In rock climbing, mountaineering, and other climbing disciplines, climbers give a grade to a climbing route or boulder problem, intended to describe concisely the difficulty and danger of climbing it. Different types of climbing (such as spo ...

Vehicles

* A-3 lifeboat, a 1947 lifeboat for carrying by the SB-29 Superfortress * Abrial A-3 Oricou, a French touring aircraft designed in 1927 * Audi A3, a model of automobile *

Aussat (Optus) A3 This is a list of the satellites operated by Optus, an Australian telecommunications company. The satellite communications facility is located at Belrose on Sydney's Northern Beaches. Optus' satellites are divided into 4 classes A, B, C and D. As ...

, a 1987 Australian telecommunication satellite *

Bavarian A III The Bavarian A III 2-2-2 engines were German steam locomotives in service with the Royal Bavarian State Railways (''Königlich Bayerische Staatsbahn''). Once again these engines were used to experiment with a short boiler and Meyer expansion val ...

, an 1851 German steam locomotive model *

Chery A3 The Chery A3 is a compact car built by the Chinese manufacturer Chery between 2008-2015, offered as a 4-door sedan and as a 5-door hatchback with a 0.27cx. It was revealed for the first time as a concept car at the 2006 Beijing Motor Show and ...

, a compact car *

LNER Gresley Classes A1 and A3 The London and North Eastern Railway LNER Gresley Classes A1 and A3 locomotives represented two distinct stages in the history of the British "Pacific" steam locomotives designed by Nigel Gresley. They were designed for main line passenger se ...

, a Pacific Locomotive Designed by Sir Nigel Gresley *

Prussian A 3 Prussia, , Old Prussian: ''Prūsa'' or ''Prūsija'' was a German state on the southeast coast of the Baltic Sea. It formed the German Empire under Prussian rule when it united the German states in 1871. It was ''de facto'' dissolved by an e ...

, a 1910 Prussian railbus *

SP&S Class A3 Spokane, Portland and Seattle Railway's Class A-3 was a class of 0-6-0 steam locomotive A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by bu ...

, a 1914 steam locomotives class

Weapons and military

* A-3 Falcon, a variant of the Curtiss Falcon, an attack aircraft manufactured by the Curtiss Aircraft Company *

A-3 Skywarrior The Douglas A-3 Skywarrior is a jet-powered strategic bomber that was developed and produced by the Douglas Aircraft Company. It was designed by Douglas on behalf of the United States Navy, which sought a carrier-capable strategic bomber. Durin ...

, a strategic bomber manufactured by Douglas Aircraft Company *

AUG A3 The Steyr AUG () is an Austrian bullpup assault rifle chambered for the 5.56×45mm NATO intermediate cartridge, designed in the 1960s by Steyr-Daimler-Puch, and now manufactured by Steyr Arms GmbH & Co KG. It was adopted by the Austrian Army ...

, a variant of the Austrian Steyr AUG rifle * Fokker A.III, a 1915 armed version of the Fokker M.5 aircraft * HMS ''A3'', a British A-class submarine of the Royal Navy * ''Kampfgeschwader'' 200, from its historic ''Geschwaderkennung'' code with the Luftwaffe in World War II *

Polaris A-3 missile The UGM-27 Polaris missile was a two-stage solid-fueled nuclear-armed submarine-launched ballistic missile (SLBM). As the United States Navy's first SLBM, it served from 1961 to 1980. In the mid-1950s the Navy was involved in the Jupiter missi ...

, an American submarine-launched missile *

Wendes Artillery Regiment The Wendes Artillery Regiment ( sv, Wendes artilleriregemente), designation A 3, was a Swedish Army artillery regiment that traced its origins back to the 17th century. The regiment's soldiers were originally recruited from Scania, where it was g ...

, a former Swedish Army artillery regiment, by designation * A3, the staff designation for air force headquarters staff concerned with operations ** A3 Air Operations Branch, of the

Joint Force Air Component Headquarters The Joint Force Air Component Headquarters (JFACHQ) is the United Kingdom's deployable air command and control unit. The JFACHQ is run by the Royal Air Force with representation from the other services. The JFACHQ has members from the operatio ...

UK * USS ''Grampus'' (SS-4), a ''Plunger''-class submarine of the United States Navy *

Aggregate 3 The Aggregat series (German for "Aggregate") was a set of ballistic missile designs developed in 1933–1945 by a research program of Nazi Germany's Armed Forces ( Wehrmacht). Its greatest success was the A4, more commonly known as the V-2. ...

, the 3rd design in the Aggregate family of rockets, precursor to the V-2 rocket, developed by the Germans during World War II

Other uses

* A₃, an example of a

root system In mathematics, a root system is a configuration of vectors in a Euclidean space satisfying certain geometrical properties. The concept is fundamental in the theory of Lie groups and Lie algebras, especially the classification and representatio ...

with numerous physical and geometrical applications * A-3 visa, a document given to employees of A-1 and A-2 Visa Holders who are representing a foreign government inside the U.S. * A3, the code for permission to use specific land or premises for restaurants and cafés in

town and country planning in the United Kingdom Town and country planning in the United Kingdom is the part of English land law which concerns land use planning. Its goal is to ensure sustainable economic development and a better environment. Each country of the United Kingdom has its own ...

* A3 roads, in several countries *

A-003 A-003 was the fourth abort test of the Apollo spacecraft. This particular flight is notable because during the abort test flight, an actual abort situation occurred, and further proved the Apollo launch escape system (LES). The CM was successfull ...

, the fourth abort test of the Apollo spacecraft * Biu-Mandara A.3 languages, an Afro-Asiatic family of languages spoken in Cameroon and Nigeria * Cowon A3, an audio media player *

Aegean Airlines Aegean Airlines S.A. ( el, Αερογραμμές Αιγαίου Ανώνυμη Εταιρεία ''Aeroporía Aigaíou Anónimi Etairía'', ) is the flag carrier airline of Greece and the largest Greek airline by total number of passengers carr ...

, by IATA code *

Tonga Tonga (, ; ), officially the Kingdom of Tonga ( to, Puleʻanga Fakatuʻi ʻo Tonga), is a Polynesian country and archipelago. The country has 171 islands – of which 45 are inhabited. Its total surface area is about , scattered over in ...

, by aircraft registration code *

ARITH-MATIC :''You may have been looking for arithmetic, a branch of mathematics.'' ARITH-MATIC is an extension of Grace Hopper's A-2 programming language, developed around 1955. ARITH-MATIC was originally known as A-3, but was renamed by the marketing depar ...

, as the former name for this programming language * "Agora! Anarchy! Action!", a slogan for Agorism taken from the ''

New Libertarian Manifesto ''New Libertarian Manifesto'' is a libertarian philosophical treatise by Samuel Edward Konkin III. It is the first explanation of agorism, a philosophy created by Konkin. Konkin proffers various arguments of how a free society would function as ...

'' by Samuel Edward Konkin III *

A3 problem solving A3 problem solving is a structured problem-solving and continuous-improvement approach, first employed at Toyota and typically used by lean manufacturing practitioners.; ; It provides a simple and strict procedure that guides problem solving by w ...

, a structured problem solving and continuous improvement approach, first employed at Toyota * Samsung Galaxy A3, a smartphone manufactured by Samsung Electronics * Samsung Galaxy A03, a smartphone manufactured by Samsung Electronics * A³ (A-cubed), an

Airbus Airbus SE (; ; ; ) is a European multinational aerospace corporation. Airbus designs, manufactures and sells civil and military aerospace products worldwide and manufactures aircraft throughout the world. The company has three divisions: '' ...

start-up in the Silicon Valley *

A3 (TV channel) TV3 (in ar, الجزائرية الثالثة), also known as El Ikhbariya (in ar, الجزائرية الإخبارية) and formerly Algeria 3 (or simply A3), is the third Algerian public national television news channel. It is part of the sta ...

, an Algerian public national television channel also known as Thalitha TV * RED A03, an aircraft diesel engine by German company Red Aviation GmbH