—n. a person filled with excessive and often misguided enthusiasm for something.
—adj. excessively enthusiastic.
Derivatives:
fanatical adj. fanatically adv. fanaticism n. fanaticize v.intr. & tr. (also -ise).
Etymology: F fanatique or L fanaticus f. fanum temple (orig. in religious sense)
Useful english dictionary. 2012.