stream has 11 distinct synonyms spread across 8 of its 10 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. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
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.
a natural body of running water flowing on or under the earth
to extend, wave or float outward, as if in the wind
“their manes streamed like stiff black pennants in the wind”
exude profusely
“She was streaming with sweat”
move in large numbers
“people were pouring out of the theater”
Synonyms, antonyms and the broader and narrower relations for stream come from Princeton University’s WordNet. Full sources and licences.
rain heavily
“Put on your rain coat-- it's pouring outside!”