historical has 2 distinct synonyms spread across 2 of its 4 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 ahistorical.
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.
of or relating to the study of history
“historical scholars”
belonging to the past; of what is important or famous in the past
“historic victories”
used of the study of a phenomenon (especially language) as it changes through time
“diachronic linguistics”
1 of the 4 recorded senses carries no synonym, antonym or related term, so it is not shown above. Every sense, with its definition and examples, is on the full entry for historical.
Synonyms, antonyms and the broader and narrower relations for historical come from Princeton University’s WordNet. Full sources and licences.