go-cart has 13 distinct synonyms spread across 3 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.
an enclosing framework on casters or wheels; helps babies learn to walk
wheeled vehicle that can be pushed by a person; may have one or two or four wheels
“he used a handcart to carry the rocks away”
a small vehicle with four wheels in which a baby or child is pushed around
Synonyms, antonyms and the broader and narrower relations for go-cart come from Princeton University’s WordNet. Full sources and licences.