adjective Also de·mo·ni·a·cal [dee-muh-nahy-uh-kuhl] /ˌdi məˈnaɪ ə kəl/.
Origin of demoniac
Examples from the Web for demoniac
But of the demoniac fury of both parties one at a distance can form no idea.Personal Recollections of the War of 1861|Charles Augustus Fuller
We used to look with awe upon the "still woman," and think of the demoniac of Scripture who had a "dumb spirit."Yankee Gypsies|John Greenleaf Whittier
The beast bristled in demoniac wrath, spat with malignant venom, and shot out its claws.Simon the Jester|William J. Locke
The walls of wood were soon set on fire, and, through flame and smoke, the demoniac assailants rushed into the city.The Empire of Russia|John S. C. Abbott
It was in the evolution of the demoniac that the divine appeared.The Lords of the Ghostland|Edgar Saltus
adjective also: demoniacal (ˌdiːməˈnaɪəkəl)
c.1400, "possessed, insane," earlier (late 14c.) as a noun, "one who is possessed," from Late Latin daemoniacus (c.200), from Greek daimoniakos "possessed by a demon," from diamon (see demon).