List of acronyms and initialisms: A
This list contains acronyms, initialisms, and pseudo-blends that begin with the letter A.
For the purposes of this list:
- acronym = an abbreviation pronounced as a series of constituent letters, e.g., SARS = severe acute respiratory syndrome
- initialism = an abbreviation pronounced wholly or partly using the names of its constituent letters, e.g., CD = compact disc
- pseudo-blend = an abbreviation whose extra or omitted letters means that it cannot stand as a true acronym, initialism, or portmanteau (a word formed by combining two or more words).
- (a) = acronym in the example: SARS – (a) Severe acute respiratory syndrome
- (i) = initialism in the example: CD – (i) Compact disc
- (p) = pseudo-blend in the example: UNIFEM – (p) United Nations Development Fund for Women
- (s) = symbol (none of the above, representing and pronounced as something else; for example: MHz – Megahertz)
(Main list of acronyms and initialisms)
A0–9
- A2ATD or A2ATD – (i) Anti-Armour Advanced Technology Demonstration
- A2C2 or A2C2 – (i) Army Airspace Command and Control
- A4 – many, including a European standard office paper size; see entry
AA
AB
AC
- aC – (s) Attocoulomb
- Ac – (s) Actinium
- AC – (i) Adriamycin-Cyclophosphamide (chemotherapy) – Air Conditioning – Aircraftman – Alternating Current – ante Christum (Latin, "before Christ"; see BC) – ante cibum (Latin, "before meals") – (s) Antigua and Barbuda (FIPS 10-4 country code) – (i) Associazione Calcio (Italian, "football (soccer) club") – Altocumulus
- A/C – (i) Air Conditioned/Conditioning – Aircraft
- AC1 – Aircraftman 1st Class
- AC2 – Aircraftman 2nd Class
- ACA – (i) Airspace Control Authority – Airspace Co-ordination Area – A Current Affair
- ACARS – (a) Aircraft Communications Addressing and Reporting System
- ACAS – (a) Aboriginal Children's Advancement Society – Advisory, Conciliation and Arbitration Service
- ACB – (i) Asociación de Clubes de Baloncesto (Spanish for "Association of Basketball Clubs")
- ACC – (i) U.S. Air Combat Command – Air Component Commander – Altocumulus castellanus – Atlantic Coast Conference – Automatic Climate Control – Area Control Center, Alpine Club of Canada
- ACCA – (i) The Association of Chartered Certified Accountants – Automatic Cloud Cover Assessment
- ACCAC – (a) Awdurdod Cymwysterau, Cwricwlwm ac Asesu Cymru (Qualifications, Curriculum and Assessment Authority for Wales)
- ACCD – American Coalition of Citizens with Disabilities
- ACCS – (i) Air Communications and Control Squadron
- ACDA – (i) Arms Control & Disarmament Agency
- ACDC – (i) Alternating Current Direct Current – the name of an Australian rock music band – a term for a bisexual person
- A/Cdre – Air Commodore
- ACDT – (a) Apple Certified Desktop Technician – (a) Australian Central Daylight Time
- ACE – (a) Air Combat Emulator (computer game) – Allied Command Europe – Armored Combat Earthmover – Automatic Computing Engine
- ACES – (a) Auxiliary Campus Enterprises and Services of Alfred State College – Aerolíneas Centrales de Colombia
- ACF – (i) American Car and Foundry – American Culinary Federation – Administration for Children and Families
- ACHT – (i) Average Call Hold Time
- ACID – (a) Atomicity, Consistency, Isolation, and Durability (in databases)
- ACINT – (p) Acoustic Intelligence
- ACK – (p) Acknowledge (telecommunications; cf. NAK)
- ACL
- ACLJ – (i) American Center for Law and Justice
- ACLOS – (i) Automatic CLOS (missile control system)
- ACLS – (i) American Council of Learned Societies
- ACLU
- ACM – many, including Association for Computing Machinery; see entry
- ACMC – (i) (U.S.) Assistant Commandant of the Marine Corps
- ACN – (i) Airborne Communications Node – Australian Company Number (number issued by the Australian government as registration of a limited liability company)
- ACO – (i) Airspace Control Order
- ACOBA – (a) Advisory Committee on Business Appointments
- ACOG – (a) American College of Obstetricians and Gynecologists
- ACOM – (p) (U.S.) Atlantic Command
- ACORN – (a) Association of Community Organizations for Reform Now
- ACP – (i) Air Control Point – African, Caribbean and Pacific Group of States
- ACR – (i) Advanced Concepts and Requirements
- ACRI – (p) African Crisis Initiative
- ACRT – (i) Advanced Concepts Research Tool simulator
- ACS – (i) Affiliated Computer Services (NYSE ACS) – American Cancer Society – American Chemical Society – Association of Caribbean States – Australian Computer Society – Alaska Communications Service
- ACSC – (i) Army Command and Staff College (various nations)
- ACST – (i) Australian Central Standard Time
- ACST – (i) American Cooperative School of Tunis
- ACT – (i) Adaptive Control of Thought (cognitive model) – Australian Capital Territory – American College Test (ing Program)
- ACTD – (i) Advanced Concept Technology Demonstration
- ACTF – (i) Australian Children's Television Foundation – (U.S.) Army Constructive Training Federation
- ACT-R – (i) ACT-Rational (cognitive model)
- ACT-R/PM – (i) ACT-R/Perceptual-Motor (cognitive model)
- ACTU – (i) Australian Council of Trade Unions
- ACU – (a) American Conservative Union
- ACUF – (i) BGN Advisory Committee on Undersea Features – (a) American Conservative Union Foundation
- ACV – (i) Armoured Combat Vehicle
AD
- AD – (i) Air Defence – (s) Andorra (ISO 3166 digram) – (i) Anno Domini (Latin, "In the year of our Lord")
- A/D – (i) Analog/Digital
- ADA – (i) Air Defence Artillery – American Dental Association – Assistant District Attorney – Americans with Disabilities Act (see also the similar but non-acronymic Ada programming language)
- ADAC – (a/i) Allgemeiner Deutscher Automobil-Club (German, "General German Automobile Club")
- ADAGE – (a) Air Defense Air to Ground Engagement (simulation)
- ADAP – (i) AIDS Drug Assistance Program
- ADAS – (a/i) Asiago-DLR Asteroid Survey
- ADAT – (i) Alesis Digital Audio Tape (recording format)
- ADatP – (p) Automated Data Processing
- ADATS – (i) Agricultural Development and Training Society – Air Defence Anti-Tank System – Australian Defence Air Traffic System
- ADB – (i) Asian Development Bank
- ADC – (i) Aide De Camp – U.S. Air Defense Command (1946–1992) – Apple Display Connector – Program Against Digital Counterfeiting of Currency
- ADCTS – (i) Advanced Distributed Combat Training System
- ADD – (i) Analog Digital Digital (CD quality) – Attention-Deficit Disorder – Administration on Developmental Disabilities
- ADDIE – (i) Analyze Design Develop Implement and Evaluate
- ADDNS – (i) Advanced Deployable Day/Night Simulation
- ADF – (i) Australian Defence Force – African Development Foundation
- ADGB – Air Defence of Great Britain
- ADHD – (i) Attention-Deficit Hyperactivity Disorder
- ADHS – (i) Attention-Deficit Hyperactivity Syndrome
- ADI – (i) Acceptable/Allowable Daily Intake
- ADIZ – (a/i) Air Defence Identification Zone
- ADL – (i) Anti-Defamation League
- ad loc. – (p) ad locum (Latin, "to/at the place")
- ADM – (i) Administrative – (s) – Admiral, and the U.S. Public Health Service Commissioned Corps – Archer Daniels Midland – Assistant Deputy Minister
- ADOA – (a/i) Air Defence Operations Area
- ADP – (i) Adenosine DiPhosphate – Army Doctrine Publication (UK, Canada, Australia) – Automatic/Automated Data Processing
- ADRG – (p) Arc-second Raster Chart (ARC) Digitized Raster Graphics
- ADS – (a/i) Active Denial System – Astrophysics Data System – Attention Deficit Syndrome
- ADSR – (i) Attack, Decay, Sustain, Release (sound envelope specification)
- ADT – (i) Atlantic Daylight Time (UTC-3 hours)
- ADTB – (i) Army Doctrine and Training Bulletin
- adv. – (p) adversus (Latin, "against")
- ADW – (i) Air Defence Warning
AE
AF
AG
AH
AI
AJ
AK
AL
AM
AN
AO
AP
AQ
AR
AS
AT
- aT – (s) Attotesla
- At – (s) Astatine
- AT – (i) Anti-Tank – (s) Ashmore and Cartier Islands (FIPS 10-4 territory code) – Austria (ISO 3166 digram) – (i) Advanced Technology (IBM Personal Computer/AT)
- ATA – (i) Advanced Technology Attachment (IBM Personal Computer) – Afghan Transitional Authority – Allen Telescope Array – (s) Antarctica (ISO 3166 trigram)
- ATAC – (a) Air Transportable Acoustic Communications
- ATACMS – (p) Army TACtical Missile System
- ATAPI – (a) Advanced Technology Attachment Packet Interface
- ATAS – (a) Air-To-Air Stinger (missile)
- ATAT – (a) Aiken Tactical Airsoft Team / Star Wars vehicle
- ATB – (i) Active Time Battle – (s) British Antarctic Territory (ISO 3166 trigram; merged with AQ in 1979)
- ATC – (i) Air Traffic Control – Air Training Corps – U.S. Air Transport Command (1942–1948)- Athletic Trainer, Certified (www.nata.org)
- ATCCIS – (i) Army Tactical Command and Control Information System
- ATESS – (i) Aerospace and Telecommunications Engineering Support Squadron
- ATF – (s) French Southern Territories (ISO 3166 trigram) – (i) (U.S.) Bureau of Alcohol, Tobacco, Firearms and Explosives (from its previous name, which did not include "Explosives")
- ATG – (s) Antigua and Barbuda (ISO 3166 and FIFA trigram)
- ATGM – (i) Anti-Tank Guided Missile
- ATGW – (i) Anti-Tank Guided Weapon
- ATI – (i) Allied Telesyn International, Inc.
- Atisbo – a Local Government Area in Nigeria named for constituent communities (Ago-Are, Tede, Irawo, Sabe, Baasi, Ofiki and Owo)
- ATK – (p) Attack
- ATL – (p) Atlanta, Georgia, the largest city and capital of Georgia
- ATLAS – (a) All-Terrain Lifter Army System – (p) Assessment Tool for LAnd Systems
- ATM – (i) Automated Teller Machine – Asynchronous Transfer Mode – At The Moment
- ATN – (s) Dronning Maud Land (ISO 3166 trigram; merged with AQ in 1983)
- ATO – (i) Air Tasking Order – Australian Taxation Office
- ATP – (i) Adenosine TriPhosphate – Allied Tactical Publication – Ammunition Transfer Point
- ATSD – (p) (U.S.) Assistant to the Secretary of Defense
- ATSDR – (i) Agency for Toxic Substances and Disease Registry
- AT&T – (i) American Telephone and Telegraph (U.S. company, also known as "Ma Bell")
- ATV – (i) All-Terrain Vehicle
- ATWA – (a) Air, Trees, Water, Animals
AU
AV
AW
AX
AY
AZ