fanatic Meaning, Definition & Usage

  1. noun a person motivated by irrational enthusiasm (as for a cause)
    fiend.
    • A fanatic is one who can't change his mind and won't change the subject"--Winston Churchill
  2. adjective satellite marked by excessive enthusiasm for and intense devotion to a cause or idea
    rabid; overzealous; fanatical.
    • rabid isolationist

WordNet

Fa*nat"ic adjective
Etymology
L. fanaticus inspired by divinity, enthusiastic, frantic, fr. fanum fane: cf. F. fanatique. See Fane.
Definitions
  1. Pertaining to, or indicating, fanaticism; extravagant in opinions; ultra; unreasonable; excessively enthusiastic, especially on religious subjects; as, fanatic zeal; fanatic notions.
    But Faith, fanatic Faith, once wedded fast To some dear falsehood, hugs it to the last. T. Moore.
Fa*nat"ic noun
Definitions
  1. A person affected by excessive enthusiasm, particularly on religious subjects; one who indulges wild and extravagant notions of religion.
    There is a new word, coined within few months, called fanatics, which, by the close stickling thereof, seemeth well cut out and proportioned to signify what is meant thereby, even the sectaries of our age. Fuller (1660).
    Fanatics are governed rather by imagination than by judgment. Stowe.

Webster 1913