WordNet records no synonym and no antonym for anchovy. 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.
tiny fishes usually canned or salted; used for hors d'oeuvres or as seasoning in sauces
small herring-like plankton-eating fishes often canned whole or as paste; abundant in tropical waters worldwide
Synonyms, antonyms and the broader and narrower relations for anchovy come from Princeton University’s WordNet. Full sources and licences.