enthusiast

noun

Etymology: From Ancient Greek ἐνθουσιαστής (enthousiastḗs, “an enthusiast, a zealot”), from ἐνθουσιάζειν (enthousiázein, “(intransitive) be inspired or possessed by a god, be rapt, be in ecstasy, (transitive) inspire”): see enthusiasm.

1. A person filled with or guided by enthusiasm.

   “But Charles Aubyn (for it was he) had, like most enthusiasts, overcalculated the influence of his eloquence; surprise had alone procured him a hearing, and the bold cavaliers around were little in the mood for a homily.”

   “I would challenge any rock enthusiast to refrain from tapping his/her foot when listening to such music.”

2. A person exhibiting over-zealous religious fervour.