shear has 1 distinct synonym spread across 1 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.
Synonyms, antonyms and the broader and narrower relations for shear come from Princeton University’s WordNet. Full sources and licences.
cut or cut through with shears
“shear the wool off the lamb”
become deformed by forces tending to produce a shearing strain
(physics) a deformation of an object in which parallel planes remain parallel but are shifted in a direction parallel to themselves
“the shear changed the quadrilateral into a parallelogram”
a large edge tool that cuts sheet metal by passing a blade through it