| AAI | Airport Authority of India |
| ABG | Arterial Blood Gas |
| AC | Alternating Current, Air Conditioner |
| ACC | Associated Cement companies |
| ACCA | Association of Certified chartered accountants |
| ADB | Asian Development Bank |
| ADCA | Advance Diploma in Computer Applications |
| ADIDAS | Adolf Adi Dassler |
| ADS | Acquired demyelinating syndrome, aiming down sights |
| AI | Artificial Intelligence |
| ALU | Arithmetic Logic Unit |
| APC | Armoured Personnel Carrier |
| APMC | Agricultural Produce Market Committee |
| ASPC | Assam Public Service Commission |
| ATM | Automated teller machine, Air traffic management |
