reorganization has 3 distinct synonyms spread across 1 of its 2 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.
the imposition of a new organization; organizing differently (often involving extensive and drastic changes)
“a committee was appointed to oversee the reorganization of the curriculum”
an extensive alteration of the structure of a corporation or government
“after the takeover there was a thorough reorganization”
Synonyms, antonyms and the broader and narrower relations for reorganization come from Princeton University’s WordNet. Full sources and licences.
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.