distrustful has no recorded synonym. 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. Its one recorded opposite is trustful.
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.
having or showing distrust
“a man of distrustful nature”
Synonyms, antonyms and the broader and narrower relations for distrustful come from Princeton University’s WordNet. Full sources and licences.