unsold 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 sold.
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.
not disposed of by purchase
“the house has been on the market almost a year and is still unsold”
Synonyms, antonyms and the broader and narrower relations for unsold come from Princeton University’s WordNet. Full sources and licences.