render has 20 distinct synonyms spread across 11 of its 14 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.
cause to become
“The shot rendered her immobile”
coat with plastic or cement
“render the brick walls in the den”
restate (words) from one language into another language
“I have to translate when my in-laws from Austria visit the U.S.”
a substance similar to stucco but exclusively applied to masonry walls
Synonyms, antonyms and the broader and narrower relations for render come from Princeton University’s WordNet. Full sources and licences.