unsophisticated has 5 distinct synonyms spread across 3 of its 3 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.
not wise in the ways of the world
“either too unsophisticated or too honest to promise more than he could deliver”
lacking complexity
“small and uncomplicated cars for those really interested in motoring”
Synonyms, antonyms and the broader and narrower relations for unsophisticated come from Princeton University’s WordNet. Full sources and licences.
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.