potency has 10 distinct synonyms spread across 4 of its 4 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. Its one recorded opposite is impotency.
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 power or right to give orders or make decisions
“he has the authority to issue warrants”
capacity to produce strong physiological or chemical effects
“the toxin's potency”
the state of being potent; a male's capacity to have sexual intercourse
Synonyms, antonyms and the broader and narrower relations for potency come from Princeton University’s WordNet. Full sources and licences.