| Acronym | Definition |
|---|
| ABACUS | a Branch and Cut System |
| ABACUS | Association of Building Societies and Credit Unions (Australia) |
| ABACUS | Armed Forces Billing and Collection Utilization Solution (Military Health System) |
| ABACUS | Arctic Biosphere Atmosphere Coupling at Multiple Scales |
| ABACUS | Architecture and Building Aids Computer Unit |
| ABACUS | Advanced Battlefield Computer Simulation |
| ABACUS | Automated Budget Analysis/Centralized User System (AFMC system) |
| ABACUS | Association of Bibliographic Agencies of Britain, Australia, Canada and the United States |
| ABACUS | Association for British and Chinese University Students (UK) |
| ABACUS | Air Battle Analysis Center Utility System |
| ABACUS | Austere Backup Communications Unmanned System |