Malevolent spirits
Evil spirits
Disembodied entities, believed to be malevolent unless appropriately propitiated.
The distinction drawn between demons and spirits is considered somewhat artificial, in that either may be beneficent or maleficent. Spirits are often considered beneficent, unless inappropriately propitiated, when they become demonic. Both are normally distinguished from ghosts or souls of the dead. Demons and spirits originally, and in tribal cultures today, had a more positive connotation, although in many cultures no effort is made to distinguish them as either good or evil. Demon is etymologically equivalent to the Sanskrit 'deva'. This connotation has been transformed into an evil one through Christian condemnation of paganism.
Belief in the malevolent potential of demons and spirits is widespread in tribal and peasant cultures and wherever elements of animism and fetichism persist. In the past, demons have been considered a calamity of the same order as fire, pestilence, floods and famine. The activities of demons continue to be of special concern to certain religious groups, notably charismatic Christians, as an explanation when medical or counselling efforts had inexplicably failed in healing the sick.
Aggravated by 
(F) Fuzzy exceptional problems