| | ABCL | | As Built Configuration List |
| | ABITHIWTIDB | | A bird in the hand is worth two in the bush |
| | ABN | | Australian Business Number |
| | abs | | abdominal muscles |
| | abs | | absolute |
| | abs | | Antilock Braking System |
| | abv | | alcohol by volume |
| | ACD | | Alt Control Delete |
| | ACE | | Access Control Entry |
| | ACE | | Application Computing Environment |
| | ACK | | ache |
| | ACK | | acknowledgement |
| | ACLU | | American Civil Liberties Union |
| | ACMS | | Advanced Content Management System |
| | ACNA | | Access Carrier Name Abbreviation |
| | ACRONYM | | abbreviated coded rendition of name yielding meaning |
| | ACRONYM | | an abbreviation formed from the initial letters of words |
| | AD&D | | Accidental Death & Dismemberment |
| | AD&D | | Advanced Dungeons and Dragons |
| | ADAD | | Another Day Another Dollar |
| | ADBB | | all done bye bye |
| | ADBB | | all done, bye, bye |
| | ADC | | automated data collection |
| | ADCOMSUBORDCOMPHIBSPAC | | Administrative Command, Amphibious Forces, Pacific Fleet Subordinate Command |
| | ADCP | | Air Defense Communications Platform |
| | ADHD | | attention deficit hyperactive disorder |
| | adidas | | all day i dream about sex |
| | adidas | | all day i dream about sex. |
| | ADIH | | another day in hell |
| | ado | | active data objects |
|