go out has 6 distinct synonyms spread across 2 of its 6 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 come in.
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.
Synonyms, antonyms and the broader and narrower relations for go out come from Princeton University’s WordNet. Full sources and licences.
take the field
“The soldiers went out on missions”
become extinguished
“The lights suddenly went out and we were in the dark”