graph has 6 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.
a visual representation of the relations between certain quantities, represented as points, plotted with reference to a set of axes
a visual display of information
a written symbol that is used to represent speech
“the Greek alphabet has 24 characters”
Synonyms, antonyms and the broader and narrower relations for graph come from Princeton University’s WordNet. Full sources and licences.