classified has 2 distinct synonyms spread across 1 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. Its one recorded opposite is unclassified.
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.
arranged into classes
official classification of information or documents; withheld from general circulation
“thousands of classified documents have now been declassified”
a short ad in a newspaper or magazine (usually in small print) and appearing along with other ads of the same type
Synonyms, antonyms and the broader and narrower relations for classified come from Princeton University’s WordNet. Full sources and licences.