WordNet records no synonym and no antonym for miranda rule. It is the only member of its synset, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
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 rule that police (when interrogating you after an arrest) are obliged to warn you that anything you say may be used as evidence and to read you your constitutional rights (the right to a lawyer and the right to remain silent until advised by a lawyer)
Synonyms, antonyms and the broader and narrower relations for miranda rule come from Princeton University’s WordNet. Full sources and licences.