Definition of "GI"

GI

adjective
not comparable
1. (military) Initialism of general issue. Given to a soldier by the army (as an item), rather than brought from home; or used by the army (as a procedure), and different from its civilian counterpart.
2. (medicine) Initialism of gastrointestinal.
  Quotations
  Endometriosis, which involves tissue similar to uterine tissue growing elsewhere in the body, has myriad symptoms, including GI distress, migraines, discomfort during sex and abdominal pain that can range from debilitating to excruciating.
  2023 June 20, Lauren Mechling, “The last health taboo: why are so many women still suffering with endometriosis?”, in The Guardian‎
3. (US) Initialism of government issue.
noun
countable and uncountable, plural GIs
1. (military) A member of the U.S. military.
2. (by extension) One who is demanding and strict, in the manner of a stereotypical member of the military.
3. Initialism of galvanized iron.
4. Initialism of geographical indication.
5. Initialism of glycemic index.
6. (computer graphics) Initialism of global illumination.
verb
third-person singular simple present GIs, present participle GIing, simple past and past participle GIed
1. (military) To clean aggressively.