sorrow has 7 distinct synonyms spread across 4 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 one recorded opposite is joy.
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.
an emotion of great sadness associated with loss or bereavement
“he tried to express his sorrow at her loss”
Synonyms, antonyms and the broader and narrower relations for sorrow come from Princeton University’s WordNet. Full sources and licences.
sadness associated with some wrong done or some disappointment
“he drank to drown his sorrows”
something that causes great unhappiness
“her death was a great grief to John”
the state of being sad
“she tired of his perpetual sadness”