/jee"uy"/ , n. , pl. GI's or GIs , adj., v., GI'd, GI'ing .
n.
1. a member or former member of the U.S. armed forces, esp. an enlisted soldier.
adj.
2. rigidly adhering to military regulations and practices; regimented; spit-and-polish: a platoon leader who tried to be more GI than anyone else.
3. of a standardized style or type issued by the U.S. armed forces: GI shoes; GI blankets.
4. conforming to the regulations or practices of the U.S. armed forces: Every recruit must get a GI haircut.
5. of, pertaining to, or characteristic of a U.S. enlisted person: a typical peacetime GI complaint.
v.t.
6. to clean in preparation for inspection: to GI the barracks.
v.i.
7. to follow military regulations and customs closely; shape up: You'd better learn to GI if you want to be promoted.
Also, G.I.
[ 1915-20; orig. abbr. of galvanized iron, used in U.S. Army bookkeeping in entering articles (e.g., trash cans) made of it; later extended to all articles issued (as an assumed abbrev. of government issue ) and finally to soldiers themselves ]