Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun demoniac

1 sense of demoniac

Sense 1
demoniac -- (someone who acts as if possessed by a demon)
       => monster, fiend, devil, demon, ogre -- (a cruel wicked and inhuman person)

Antonyms of adj demoniac

1 sense of demoniac

Sense 1
amuck, amok, berserk, demoniac, demoniacal, possessed (predicate) -- (frenzied as if possessed by a demon; "the soldier was completely amuck"; "berserk with grief"; "a berserk worker smashing windows")

INDIRECT (VIA insane) -> sane -- (mentally healthy; free from mental disorder; "appears to be completely sane")

Similarity of adj demoniac

1 sense of demoniac

Sense 1
amuck, amok, berserk, demoniac, demoniacal, possessed (predicate) -- (frenzied as if possessed by a demon; "the soldier was completely amuck"; "berserk with grief"; "a berserk worker smashing windows")
       => insane (vs. sane) -- (afflicted with or characteristic of mental derangement; "was declared insane"; "insane laughter")