| Abbreviation | Definition |
|---|---|
| GCTE | Global Change in Terrestrial Ecosystems |
| GCTM | Group for the Conservation of the Tropics in Mexico |
| GCTS | Ground Communications Tracking System |
| GCTS | Gas Component Test Stand |
| GCU | Gyro Coupling Unit |
| GCU | Ground Cooling Unit |
| GCU | Generator Control Unit |
| GCU | General Control Unit |
| GCU | Guidance and Counseling Unit |
| GCV | Gaseous Oxygen Control Valve |
| GCVS | General Catalog Of Variable Stars |
| GD | Group Discussion |
| GD | Gauchers Disease |
| GD | Grave Diggers |
| GD | Graphic Designer |
| GD | Graphic Design |
| GDA | Glandular Developmental Arrest |
| GDA | Gwadar Development Authority |
| GDA | Golden Doodle Award |
| GDBS | Generalized Data Base System |
| GDC | Genetic Disease Control |
| GDC | Guglielmi Detachable Coil |
| GDC | Gyro Display Coupler |
| GDC | General Dynamics Convair |
| GDCF | Gross Domestic Capital Formation |
| GDCLS | General Dynamics Commercial Launch Services |
| GDEP | Graduate Diploma of Editing and Publishing |
| GDEP | Global DOTS Expansion Plan |
| GDF | Gasoline Dispensing Facilities |
| GDI | Graphics Device Interface |
| GDI | Gender Development Index |
| GDI | Global Defense Initiative |
| GDL | Grand Duchy of Luxembourg |
| GDL | Graduated Driver Licensing |
| GDM | Gestational Diabetes Mellitus |
| GDM | Gestational Diabetes Melitus |
| GDN | Goods Delivery Note |
| GDP | Gross Domestic Product |
| GDP | Guanosine Diphosphate |
| GDP | Generalized Documentation Processor |
| GDP | Good Debt Payments |
| GDPFS | Global Data-processing and Forecast System |
| GDR | Global Depository Receipt |
| GDR | German Democratic Republic |
| GDRIMS | Glow-Discharge Resonance Ionization Mass Spectrometry |
| GDRs | Global Depositary Receipts |
| GDS | Great Dark Spot |
| GDS | General Depreciation System |
| GDSD | Ground Data Systems Division |
| GDSIRD | Ground Data System Information Requirements Document |