disembodied spirit; ghost; devil; (suffix) person with a certain vice
Pictograph of a person (人) with the head of a ghost/demon (甶). 厶 was later added as a decorative mark.
《說文》：“鬼，人所歸為鬼。从人，象鬼頭。鬼陰氣賊害，从厶。，古文从示。”