parole has 5 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.
a secret word or phrase known only to a restricted group
“he forgot the password”
(law) a conditional release from imprisonment that entitles the person to serve the remainder of the sentence outside the prison as long as the terms of release are complied with
release a criminal from detention and place him on parole
“The prisoner was paroled after serving 10 years in prison”
Synonyms, antonyms and the broader and narrower relations for parole come from Princeton University’s WordNet. Full sources and licences.