| Acronym | Definition |
|---|
| GCAS | Ground Collision Avoidance System |
| GCAS | Global Customer Assistance Service |
| GCAS | Gulf Centre for Aviation Studies (Abu Dhabi, United Arab Emirates) |
| GCAS | Greater Cincinnati Aquarium Society |
| GCAS | Guilford County Animal Shelter |
| GCAS | General Conference Auditing Service |
| GCAS | General Conference Auditing Service (Seventh-Day Adventist Church) |
| GCAS | Graduate Certificate in Antarctic Studies |
| GCAS | Gold Coast Aquarium Society (Australia) |
| GCAS | Greater City Aquarium Society |
| GCAS | Grants and Contracts Accounting Services |
| GCAS | Ground Alert Close Air Support |
| GCAS | Gloucester County Animal Shelter |
| GCAS | Genesee County Animal Shelter |
| GCAS | Gibson County Animal Services |
| GCAS | general channel allocation scheme |
| GCAS | God's Country Astronomical Society |
| GCAS | Government Common Application System (Hong Kong) |
| GCAS | Girls Central Art School (Australia) |
| GCAS | Gas Chromatograph Analyzer Server |
| GCAS | Government Cost Accounting System, Inc. |
| GCAS | Graduate Certificate Program in Applied Statistics |
| GCAS | Global Corporate Audit Services |
| GCAS | God as Causal Agent Scale |
| GCAS | General Computing and Software |
| GCAS | General Cost Allocation System |
| GCAS | General College and Arts and Sciences |
| GCAS | Grant County Archeological Society |
| GCAS | Golden Cradle Adoption Services |
| GCAS | Graduate Course of Academic Study |
| GCAS | Great Canadian Artist Series |
| GCAS | Goth Chick Appreciation Society |