documented has 2 distinct synonyms spread across 1 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. Its one recorded opposite is undocumented.
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.
furnished with or supported by documents
“the first documented case of shark attack in those waters”
established as genuine
Synonyms, antonyms and the broader and narrower relations for documented come from Princeton University’s WordNet. Full sources and licences.