excision has 7 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.
surgical removal of a body part or tissue
the act of banishing a member of a church from the communion of believers and the privileges of the church; cutting a person off from a religious society
the act of pulling up or out; uprooting; cutting off from existence
Synonyms, antonyms and the broader and narrower relations for excision come from Princeton University’s WordNet. Full sources and licences.