| AACO | Asian Americans for Community Outreach |
|---|---|
| ACS | Army Community Service |
| ACU | Antenna Control Unit |
| ACU | Audio Control Unit |
| ADU | Air Data Unit |
| ADU | Air Defense Unit |
| ADU | Antenna Drive Unit |
| ADU | Application Data Unit |
| AEO | Association for Enterprise Opportunity |
| AIDS | Acquired Immune Deficiency Syndrome, syndróm získaného zlyhania imunity, smrteľné ochorenie, spôsobené retrovírom HIV |