unconscious has 1 distinct synonym spread across 1 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 conscious.
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.
not conscious; lacking awareness and the capacity for sensory perception as if asleep or dead
“lay unconscious on the floor”
that part of the mind wherein psychic activity takes place of which the person is unaware
2 of the 4 recorded senses carry no synonym, antonym or related term, so they are not shown above. Every sense, with its definition and examples, is on the full entry for unconscious.
Synonyms, antonyms and the broader and narrower relations for unconscious come from Princeton University’s WordNet. Full sources and licences.