good has 35 distinct synonyms spread across 20 of its 27 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 bad, evil.
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.
having desirable or positive qualities especially those suitable for a thing specified
“good news from the hospital”
morally admirable
deserving of esteem and respect
“all respectable companies give guarantees”
promoting or enhancing well-being
“an arms limitation agreement beneficial to all countries”
tending to promote physical well-being; beneficial to health
“beneficial effects of a balanced diet”
benefit
“for your own good”
(often used as a combining form) in a good or proper or satisfactory manner or to a high standard (`good' is a nonstandard dialectal variant for `well')
“the children behaved well”
completely and absolutely (`good' is sometimes used informally for `thoroughly')
“he was soundly defeated”
4 of the 27 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 good.
Synonyms, antonyms and the broader and narrower relations for good come from Princeton University’s WordNet. Full sources and licences.
articles of commerce