leverage has 2 distinct synonyms spread across 2 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 mechanical advantage gained by being in a position to use a lever
strategic advantage; power to act effectively
“relatively small groups can sometimes exert immense political leverage”
Synonyms, antonyms and the broader and narrower relations for leverage come from Princeton University’s WordNet. Full sources and licences.
investing with borrowed money as a way to amplify potential gains (at the risk of greater losses)
supplement with leverage
“leverage the money that is already available”
provide with leverage
“We need to leverage this company”