gi has 5 distinct synonyms spread across 4 of its 4 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a unit of magnetomotive force equal to 0.7958 ampere-turns
(law) a name or sign used on certain products which corresponds to a specific geographical location or origin
clean in preparation for inspection
“the soldiers GIed the barracks”
Synonyms, antonyms and the broader and narrower relations for gi come from Princeton University’s WordNet. Full sources and licences.