truss has 4 distinct synonyms spread across 2 of its 6 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.
(medicine) a bandage consisting of a pad and belt; worn to hold a hernia in place by pressure
a framework of beams (rafters, posts, struts) forming a rigid structure that supports a roof or bridge or other structure
(architecture) a triangular bracket of brick or stone (usually of slight extent)
Synonyms, antonyms and the broader and narrower relations for truss come from Princeton University’s WordNet. Full sources and licences.
tie the wings and legs of a bird before cooking it