My definition of an ideological or religios fundamentalist (or the one of Thomas Binder)
(1 out of 5 criteria is enough):

1. Who sees his “truth” as the absolute and only one possible and right.
2. Who sees members of his “group” as a priori better people than members of other “groups”.
3. Who accepts a significant restriction of the freedom of others for winning his own freedom.
4. Who wants to put laws given by his leader / prophet / “God” over the (human made) legal laws.
5. Who can’t (also) laugh about himself and about his leader / prophet / “God”.

Source: Thomas Binder on Facebook