| Abbreviation | Definition |
|---|---|
| GBC | Garrett Boost Club |
| GBCC | Green Bay Country Club |
| GBHC | Gosport Borough Hockey Club |
| GBHC | Green Brook Hockey Club |
| GBPC | Georgian Bay Photography Club |
| GBSC | Galway Bay Sailing Club |
| GBSC | Greater Boston Soaring Club |
| GBSC | Green Bay Swim Club |
| GBTC | Greater Boston Track Club |
| GC | Gardening Club |
| GC | Giblet Club |
| GCA | Garden Club of America |
| GCA | Golf Clubmakers Association |
| GCA | Group Club Association |
| GCAC | Garden Club of Allegheny County |
| GCBC | Girton College Boat Club |
| GCBC | Grand Case Beach Club |
| GCBC | Greater China Business Club |
| GCBC | Green Coffee Buying Club |
| GCBC | Gulf Coast Bicycle Club |