inactivation has 1 distinct synonym 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. Its one recorded opposite is activation.
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.
the process of rendering inactive
“the gene inactivation system”
Synonyms, antonyms and the broader and narrower relations for inactivation come from Princeton University’s WordNet. Full sources and licences.