gull has 18 distinct synonyms spread across 4 of its 4 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.
mostly white aquatic bird having long pointed wings and short legs
fool or hoax
“The immigrant was duped because he trusted everyone”
Synonyms, antonyms and the broader and narrower relations for gull come from Princeton University’s WordNet. Full sources and licences.