spider has 1 distinct synonym spread across 1 of its 3 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.
predatory arachnid with eight legs, two poison fangs, two feelers, and usually two silk-spinning organs at the back end of the body; they spin silk to make cocoons for eggs or traps for prey
Synonyms, antonyms and the broader and narrower relations for spider come from Princeton University’s WordNet. Full sources and licences.