circuitous has 2 distinct synonyms spread across 2 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. 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.
marked by obliqueness or indirection in speech or conduct
“the explanation was circuitous and puzzling”
Synonyms, antonyms and the broader and narrower relations for circuitous come from Princeton University’s WordNet. Full sources and licences.