gb has 10 distinct synonyms spread across 6 of its 6 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 highly toxic chemical nerve agent that inhibits the activity of cholinesterase
a unit of magnetomotive force equal to 0.7958 ampere-turns
a unit of information equal to 1000 megabits or 10^9 (1,000,000,000) bits
a unit of information equal to 1000 megabytes or 10^9 (1,000,000,000) bytes
a unit of information equal to 1024 mebibytes or 2^30 (1,073,741,824) bytes
an island comprising England and Scotland and Wales
Synonyms, antonyms and the broader and narrower relations for gb come from Princeton University’s WordNet. Full sources and licences.