WordNet records no synonym and no antonym for nitrate. 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.
any compound containing the nitrate group (such as a salt or ester of nitric acid)
Synonyms, antonyms and the broader and narrower relations for nitrate come from Princeton University’s WordNet. Full sources and licences.
treat with nitric acid, so as to change an organic compound into a nitrate
“nitroglycerin is obtained by nitrating glycerol”