trunk has 8 distinct synonyms spread across 4 of its 5 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.
the main stem of a tree; usually covered with bark; the bole is usually the part that is commercially useful for lumber
luggage consisting of a large strong case used when traveling or for storage
compartment in an automobile that carries luggage or shopping or tools
“he put his golf bag in the trunk”
Synonyms, antonyms and the broader and narrower relations for trunk come from Princeton University’s WordNet. Full sources and licences.