;gastro-intestinal: in medicine ;GI: in common American usage: "government-issued", "army enlisted personnel", "Galvanized Iron", see also: GI Joe. ;gi: a two-letter English word for a judo or karate costume ;Gibraltar: ISO country code ;gilbert (Gb or Gi): a former unit of magnetomotive force or magnetic potential ;gill (gi): U.S. customary unit equal to 4 fluid ounces ;Global Illumination: In 3D computer graphics, GI is about calculating light in 3d scenes in variuos forms. Rendering used to be slow, depending on computer CPU and settings.