supernatural has 1 distinct synonym spread across 1 of its 2 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 natural.
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.
supernatural forces and events and beings collectively
“She doesn't believe in the supernatural”
not existing in nature or subject to explanation according to natural laws; not physical or material
“supernatural forces and occurrences and beings”
Synonyms, antonyms and the broader and narrower relations for supernatural come from Princeton University’s WordNet. Full sources and licences.