| Abbreviation | Definition |
|---|---|
| GWCT | Greater Walker Community Trust |
| GWCU | Georgian White Cross Union |
| GWI | Growth Works, Inc. |
| GWTA | Great Western Trail Association |
| GWTF | Georgia Wetland Trust Fund |
| GWTM | Global War on Terror Memorial |
| GWTU | George Washington Chapter, Trout Unlimited |
| GYC | Greater Yellowstone Coalition |
| GYE | Greater Yellowstone Ecosystem |
| GYF | Ghangar Youth Federation |
| GZT | Ground Zero Team |
| HA | Humanitarian Aid |
| HA | Hydrocephalus Association |
| HAA | Harvard Athletic Associaton |
| HAA | Histiocytosis Association of America |
| HAA | Hospice Association of America |
| HAAART | Homeless and Abused Animal Rescue Team |
| HABAC | Human Animal Bond Association of Canada |
| HABIT | Human Animal Bond In Tennessee |
| HACA | Henderson Allied Community Advocates |