noble has 5 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 2 recorded opposites are lowborn, ignoble.
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 or belonging to or constituting the hereditary aristocracy especially as derived from feudal times
“of noble birth”
having or showing or indicative of high or elevated character
“a noble spirit”
1 of the 5 recorded senses carries no synonym, antonym or related term, so it is not shown above. Every sense, with its definition and examples, is on the full entry for noble.
Synonyms, antonyms and the broader and narrower relations for noble come from Princeton University’s WordNet. Full sources and licences.