interdict has 7 distinct synonyms spread across 2 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.
an ecclesiastical censure by the Roman Catholic Church withdrawing certain sacraments and Christian burial from a person or all persons in a particular district
a court order prohibiting a party from doing a certain activity
destroy by firepower, such as an enemy's line of communication
Synonyms, antonyms and the broader and narrower relations for interdict come from Princeton University’s WordNet. Full sources and licences.