unreal has 3 distinct synonyms spread across 2 of its 4 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 real.
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.
lacking in reality or substance or genuineness; not corresponding to acknowledged facts or criteria
“ghosts and other unreal entities”
not actually such; being or seeming fanciful or imaginary
“this conversation is getting more and more unreal”
lacking material form or substance; unreal
“as insubstantial as a dream”
Synonyms, antonyms and the broader and narrower relations for unreal come from Princeton University’s WordNet. Full sources and licences.