dying has 3 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 nascent.
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.
in or associated with the process of passing from life or ceasing to be
“a dying man”
the time when something ends
“it was the death of all his plans”
Synonyms, antonyms and the broader and narrower relations for dying come from Princeton University’s WordNet. Full sources and licences.