correspondence has 7 distinct synonyms spread across 4 of its 5 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.
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.
communication by the exchange of letters
compatibility of observations
“there was no agreement between theory and measurement”
the relation of corresponding in degree or size or amount
(mathematics) an attribute of a shape or relation; exact reflection of form on opposite sides of a dividing line or plane
Synonyms, antonyms and the broader and narrower relations for correspondence come from Princeton University’s WordNet. Full sources and licences.