downstage has no recorded synonym. 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 upstage.
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.
the front half of the stage (as seen from the audience)
of the front half of a stage
Synonyms, antonyms and the broader and narrower relations for downstage come from Princeton University’s WordNet. Full sources and licences.
at or toward the front of the stage
“the actors moved further and further downstage”