Fanaticism is derived from the Latin word fanum, which refers to sacred places
of worship such as temples or other consecrated sites. The complete term fanaticus
means “to be put into raging enthusiasm by a deity.”2 In the modern
sense, a fanatic is simply an individual who goes to an extreme, is overly zealous
or unreasonably enthusiastic regarding an issue, idea, opinion, or action.
These ideations do not have to be of a strictly religious nature, but may also
be in regard to a personal or private matter or a larger political, social, or economic
issue. Despite the broadness of its contemporary application, it is most
commonly used in its traditional sense of religious zealousness, intolerance,
and violence.
American Journal of Islamic Social Sciences