gi

Short definition from Wiktionary

Noun

1. 1
   A martial arts uniform.
2. 2
   A member of the U.S. military.
3. 3
   One who is demanding and strict, in the manner of a stereotypical member of the military.
4. 4
   Initialism of galvanized iron.
5. 5
   Initialism of geographical indication.
6. 6
   Initialism of glycemic index.
7. 7
   Initialism of global illumination.

Adjective

1. 1
   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. 2
   Initialism of gastrointestinal.
3. 3
   Initialism of government issue.

Verb

1. 1
   To clean aggressively.