fortunate has 2 distinct synonyms spread across 2 of its 3 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 unfortunate.
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 unexpected good fortune
“other, less fortunate, children died”
supremely favored
“golden lads and girls all must / like chimney sweepers come to dust”
Synonyms, antonyms and the broader and narrower relations for fortunate come from Princeton University’s WordNet. Full sources and licences.