noun
fanatic
a person motivated by irrational enthusiasm (as for a cause)
Where it comes from
Fanatic comes from Latin fanaticus, first 'of a temple' and later 'inspired by a deity' or 'frenzied,' based on fanum, a temple or shrine.
How the meaning developed
People behaving as if divinely possessed supplied the senses frenzied and mad. English then narrowed and softened that religious frenzy into excessive, uncritical zeal, and eventually into intense enthusiasm of many kinds.
Sources
Definitions adapted from Open English WordNet where applicable. License and attribution. Word-history text comes from Lexifour’s sourced social research; pages are assembled automatically, not individually fact-checked on every update.
Updated 2026-09-25. Report a correction.