article has 1 distinct synonym spread across 1 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.
nonfictional prose forming an independent part of a publication
one of a class of artifacts
“an article of clothing”
a separate section of a legal document (as a statute or contract or will)
(grammar) a determiner that may indicate the specificity of reference of a noun phrase
bind by a contract; especially for a training period
Synonyms, antonyms and the broader and narrower relations for article come from Princeton University’s WordNet. Full sources and licences.