satisfaction has 3 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. Its one recorded opposite is dissatisfaction.
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 contentment one feels when one has fulfilled a desire, need, or expectation
“the chef tasted the sauce with great satisfaction”
state of being gratified or satisfied
“dull repetitious work gives no gratification”
(law) the payment of a debt or fulfillment of an obligation
“the full and final satisfaction of the claim”
act of fulfilling a desire or need or appetite
“the satisfaction of their demand for better services”
Synonyms, antonyms and the broader and narrower relations for satisfaction come from Princeton University’s WordNet. Full sources and licences.