WordNet records no synonym and no antonym for taxonomy. It is the only member of each of its synsets, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
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 classification of organisms into groups based on similarities of structure or origin etc
(biology) study of the general principles of scientific classification
Synonyms, antonyms and the broader and narrower relations for taxonomy come from Princeton University’s WordNet. Full sources and licences.
practice of classifying plants and animals according to their presumed natural relationships