Etymology
Advertisement

demoniac (adj.)

c. 1400, "possessed by a demon, insane," earlier (late 14c.) as a noun, demoniak, "one who is possessed, a lunatic," from Late Latin daemoniacus, from Greek daimoniakos "possessed by a demon," from diamon (see demon). From 1640s as "of or pertaining to demons or spirits;" by 1820 as "devilish." Related: Demoniacal; demoniacally.

updated on July 19, 2018

Advertisement
Advertisement
Definitions of demoniac from WordNet
1
demoniac (n.)
someone who acts as if possessed by a demon;
2
demoniac (adj.)
of, pertaining to, or like a demon or possession by a demon;
Synonyms: demoniacal / possessed
From wordnet.princeton.edu, not affiliated with etymonline.