| Acronym | Definition |
|---|
| ACOS | Arc Cosine (Inverse Cosine) |
| ACOS | American College of Surgeons |
| ACOS | Asthma-COPD (Chronic Obstructive Pulmonary Disease) Overlap Syndrome |
| ACOS | Assistant Chief of Staff (also seen as A/COS) |
| ACOS | Advanced Core Operating System |
| ACOS | Associate Chief of Staff |
| ACOS | Arc Cosine |
| ACOS | American College of Osteopathic Surgeons |
| ACOS | Advisory Committee on Safety (IEC) |
| ACOS | A Change of Seasons (Dream Theater album) |
| ACOS | A Crown of Swords (Wheel of Time; book 7) |
| ACOS | Air and Space Communications Operations Squadron (US Air Force) |
| ACOS | Australian Chamber Of Shipping |
| ACOS | Associazione Cattolica Operatori Sanitari (Italian: Catholic Association of Medics and Paramedics) |
| ACOS | Anti-Capitalist Operating System |
| ACOS | Automatic Change-Over Switch |
| ACOS | Aircraft Certification Office Subsystem |
| ACOS | Adaptive Cognitive Orthosis Shell |
| ACOS | Automated Commissary Operations System |
| ACOS | ACCS Common Operating System |
| ACOS | Army Common Operating System |
| ACOS | At Change of Shift |
