Used attributively as an abbreviation for 'government issue' or 'gastrointestinal'.
Definitionen
Of or relating to items issued by the U.S. military; standard-issue. He packed his GI canteen before heading out.
Relating to the stomach and intestines. The patient reported several GI symptoms during the consultation.
Relating to, or characterized by, the glycemic index, especially indicating a specified glycemic response. Nutritionists recommend low-GI foods to help control blood sugar levels.