D defs.my
Entry 1 sense Webster, 1913

Enthusiast

/ĕn-tho͞oz'-ē-ăstˌ/ · En·thu·si·ast · IPA /ənˈθuziˌɪst/
01 n. One moved or actuated by enthusiasm; as: (a) One who imagines himself divinely inspired, or possessed of some special revelation; a religio…
  1. 1.
    One moved or actuated by enthusiasm; as: (a) One who imagines himself divinely inspired, or possessed of some special revelation; a religious madman; a fanatic. (b) One whose mind is wholly possessed and heated by what engages it; one who is influenced by a peculiar; fervor of mind; an ardent and imaginative person.
    Enthusiasts soon understand each other.” W. Irving.