possessed or influenced by a demon
like or characteristic of a demon; fiendish
: Also ˌdemoˈniacal (ˌdiməˈnaɪəkəl
a person supposedly possessed by a demon
Webster’s New World College Dictionary, 4th Edition. Copyright © 2010 by
Houghton Mifflin Harcourt. All rights reserved.
Word origin of 'demoniac'ME demoniak < LL(Ec) daemoniacus < Gr daimoniakos