superior has 8 distinct synonyms spread across 6 of its 13 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 inferior.
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.
of high or superior quality or performance
“superior wisdom derived from experience”
of or characteristic of high rank or importance
“a superior ruler”
written or printed above and to one side of another character
having an orbit farther from the sun than the Earth's orbit
“Mars and Jupiter are the closest in of the superior planets”
one of greater rank or station or quality
the largest freshwater lake in the world; the deepest of the Great Lakes
a town in northwest Wisconsin on Lake Superior across from Duluth
a character or symbol set or printed or written above and immediately to one side of another character
2 of the 13 recorded senses carry no synonym, antonym or related term, so they are not shown above. Every sense, with its definition and examples, is on the full entry for superior.
Synonyms, antonyms and the broader and narrower relations for superior come from Princeton University’s WordNet. Full sources and licences.