Fundamentalism is a word that's been taking a beating in recent years.
At one time, its use was restricted to Christian Theology. Specifically, it was an anti-liberal movement of laymen beginning in the early 1900s in the United States. The movement was pan-denominational, and remains alive today. The movement grew out of the Niagra Bible Conference of 1895, which posited Five Points of Fundamentalism as necessary standards of belief. Christ's imminent bodily return to earth.