| Arts, Academics, and Athletics | Academic & Science |
| Alberta Association of Architects | Academic & Science |
| Academics, Athletics, and Arts | Academic & Science |
| Battery type AAA (battery size) | Academic & Science |
| Amateur Astronomers Association | Academic & Science |
| American Academy of Actuaries | Academic & Science |
| Atlanta Adventist Academy | Academic & Science |
| Architecture and Allied Arts | Academic & Science |
| Atlantean Academic Archaeologist | Academic & Science |
| Academic Achievement and Advising | Academic & Science |
| Accumulated Adjustments Account | Accounts and Finance |
| American Accounting Association | Accounts and Finance |
| Association of Accounting Administrators | Accounts and Finance |
| Anaa | Airport Code |
| Amateur Athletic Association | Associations & Organizations |
| Association of Autonomous Astronauts | Associations & Organizations |
| American Anthropological Association | Business |
| American Association of Anatomists | Business |
| Askari Asaan Account | Business |
| Anthony's Adoption Agency | Business |
| Advanced, Available, and Affordable | Business |
| Alter, Avoid, or Accept | Business |
| Angewandte Amerikanistik Anglistik | Business |
| Administrative Admission Antics | Business |
| The Agricultural Adjustment Act | Business |
| Automobile Association of America | Business |
| Animal Analysis Associates | Business |
| Agree, Amplify, and Accelerate | Business Management |
| Adult Alternative Album | Community |
| Active Affluent Adults | Community |
| Adult Album Alternative | Community |
| Attack All Around | Community |
| Arkansas Activities Association | Community |
| Australian Automobile Association | Community |
| Alternit Asscotiation Apart | Community |
| Anti-Aircraft Association | Community |
| Assorted Astro Art | Community |
| Any Art Accepted | Community |
| Awareness, Action, and Accountability | Community |
| Acoustic And Acapella | Community |
| Arrowhead Accountability Association | Community |
| Asian American Association | Community |
| Afghan Aid Association | Community |
| American Abstract Artists | Community |
| Afghan America Attractive | Community |
| Agree Acknowledge Apologize | Community |
| Active Accelerated Academy | Community |
| Adult Alternative Acoustic | Community |
| Adult Alternative Albums | Community |
| Area Agency on Aging | Community |
| Authentication, Authorization and Accounting | Computer and Networking |
| Ascii Adjust After Addition | Computer Assembly Language |
| Adequation Algorithm Architecture | Computer Hardware |
| Advanced Accelerator Applications | Computer Hardware |
| Algorithm Architecture Adequation | Computer Hardware |
| Authentication, Authorization, and Accountability | Computing |
| Automatic Artwork Alignment | Computing |
| Accuview Anti Aliasing | Computing |
| Advanced Account Access | Computing |
| Aces of Ansi Art | Computing |
| Authentication Authorisation and Accounting | Computing |
| Moon Rabbit | Cryptocurrency |
| Abulaba | Cryptocurrency |
| Asian Art Appreciation | Educational Degree |
| App Cam Automation File | File Type |
| Xtal Backup File | File Type |
| Softphrase Automation File | File Type |
| Sybase Sqlanywhere Temp File | File Type |
| Anime Addicts Anonymous | General |
| Awful, Agonizing, and Aggravating | General |
| Audax Altitude Award | General |
| Autodesk Alias Automotive | General |
| Association Auxiliere de l'Automobile | General |
| Association des Anciens d'Alpine | General |
| Automotive Advertising Agency | General |
| Arabian Auto Agency | General |
| American Ambulance Association | General |
| Associazione Attiva Automobilisti | General |
| Advanced Aluminium Architecture | General |
| Automotive Acronyms and Abbreviations | General |
| America's Auto Auction | General |
| Al-Futtaim Automotive Academy | General |
| Advanced Automotive Analytics | General |
| Asian Autosport Action | General |
| Asociacion Automovilistica Ambato | General |
| Ask Autocar Anything | General |
| Academic Automotive Association | General |
| Automobiles Anciennes de l'Agenais | General |
| Amateurs d'Automobiles Anciennes | General |
| Aircraft Airbrush Art | General |
| Association des Avocats de l'Automobile | General |
| Accuracy Always Assured | General |
| Agence Americaine Automobiles | General |
| Arms Abs and A | General |
| Aktiengesellschaft Fur Akkumulatoren Und Automobilbau | General |
| adaptive Antoulas Anderson | General |
| Authentic Available and Affirming | General |
| Army Army Army | General |
| A Authentication Authorization | General |
| Anonymous Angel Assistance | General |
| Andre Ayew Appreciation | General |
| Archery Analysis App | General |
| Annual Alpha Awards | General |
| Amateur Alcoholic A**holes | General |
| Abbreviations and Acronyms on Acronymsandslang | General |
| Austin Allegro Alert | General |
| Answer Abercrombie Associates | General |
| Agriculture and Allied Activities | General |
| Anything Anywhere Anytime | General |
| Agricultural Adjustment Act & Administration | General |
| Triple-A Meter | General |
| Agricultural Adjustment Act & Administration | General |
| Absolutely Absurd Analysis | General |
| aggressive Antoulas Anderson | General |
| Automated Aminoacid Analyses | General |
| Action on Alcohol Abuse | General |
| Asparagine AAC Asparagine | General |
| Aliya, the Atrocious Appaloosa | General |
| Alcoholic Apes Anonymous | General |
| Angband Across America | General |
| Always Add Acid | General |
| Agricultural Adjustment Act | General |
| Athlon Addicts Anonymous | General |
| Arrival Arrangements Agreements | Governmental |
| Autonomous Administrative Authority | Governmental |
| Against All Authority | Governmental |
| Auckland Automobile Association | Governmental |
| American Arbitration Association | Governmental |
| Agricultural Adjustment Administration | Governmental |
| Authority Authorization AAA | Governmental |
| Automated Airlift Analysis | Governmental |
| Authentication Authorization, Accounting | Information Technology |
| Abdominal Aortic Aneurysm | Insurance |
| Asistencia, Asesoría y Administración | International |
| Autoridad de Acueductos y Alcantarillados | International |
| Associazione Automobilistica Americana | International |
| Alianza Apostólica Anticomunista | International |
| Angle Angle Angle | Maths |
| Appropriate, Affordable, and Available | Medical |
| Amino Acid Analysis | Medical |
| A trial of Aspirin Against no Aspirin | Medical |
| Acne-Associated Arthritis | Medical |
| Acquired Aplastic Anemia | Medical |
| Acute Anxiety Attack | Medical |
| Acute Apical Abscess | Medical |
| Avoidance, Adrenaline, Allergist | Medical |
| Alacrimia-Achalasia-Addisonianism | Medical |
| Ambulance Association of America | Medical |
| American Academy of Addictionology | Medical |
| American Academy of Allergy | Medical |
| American Academy of Audiology | Medical |
| American Acupuncture Association | Medical |
| American Against Abortions | Medical |
| American Allergy Association | Medical |
| AminoAdipic Acid | Medical |
| Amyloid in Ageing and Alzheimer disease | Medical |
| Animal-Assisted Activity | Medical |
| Animal Acupuncture Academy | Medical |
| Animal Agriculture Alliance | Medical |
| Amyloid in Ageing and Alzheimer’s disease | Medical |
| Androgenic Anabolic Agent | Medical |
| Aneurysm of Ascending Aorta | Medical |
| Annual Accountability Agreement | Medical |
| Anti-Albumin Antibody | Medical |
| Aortic Arch Atherosclerosis | Medical |
| Aromatic Amino Acid | Medical |
| Arrest After Arrival | Medical |
| Arterio-Arterial Anastomosis | Medical |
| automated amino acid analysis | Medical |
| Apply to Affected Area | Medical |
| Awesome Awesome Awesome | Messaging |
| Accountants and Auditors Association | Messaging |
| American Automobile Association | Messaging |
| Alternate Assembly Area | Military and Defence |
| Anti-aircraft Artillery | Military and Defence |
| Airborne Assault Area | Military and Defence |
| Army Audit Agency | Military and Defence |
| Air Avenue of Approach | Military and Defence |
| Anarchy Armageddon Annihilation | Military and Defence |
| Awaiting Aircraft Availability | Military and Defence |
| Access All Areas | Military and Defence |
| Allied Airborne Army | Military and Defence |
| Authority Authorization Auditing | Military and Defence |
| Arrival and Assembly Area | Military and Defence |
| Assign Alternate Area | Military and Defence |
| Advanced Applications of Accelerators | Physics Related |
| Alianza Apostica Anticomunista | Regional |
| Asistencia, Asesor y Administraci? | Regional |
| Agriculture Advancing Australia | Regional |
| Ana, Tuamotu Islands, French Polynesia, South Pacific | Regional |
| Automated Atlantis Assistants | Softwares |
| Avionics Air Assembly | Space Science |
| Anglers of All Abilities | Sports |
| Australian Anglers Association | Sports |
| Average Amateur Attempt | Sports |
| Academics Arts and Athletics | Sports |
