| Abbreviation | Definition |
|---|---|
| GSI | Grain Systems Inc |
| GSI | Grason Stadler Inc |
| GSL | Grandma's Stories, LTD. |
| GSL | Great Salt Lake |
| GSLI | Gronczniak Specialty Lines Inc |
| GSM&R | Granite State Management and Resources |
| GSMB | Geological Survey and Mines Bureau |
| GSMC | Grace Semiconductor Manufacturing Corporation |
| GSMC | Gracelyn Stress Management Center |
| GSMS | Great Southern Media Services |
| GSN | Game Source Network |
| GSNC | General Steam Navigation Company |
| GSO | Golden State Overnight |
| GSO | Groep Speciale Operaties |
| GSO | Guan Sheng Optical Company |
| GSO | Gudvi, Sussman, and Oppenheim |
| GSOC | Georgia Systems Operations Corporation |
| GSOC | Gopher State One Call |
| GSOI | Grand Sud-Ouest Industrie |
| GSOS | Garden State Office Systems |