fanatic Definition

fanatic
noun

1. Someone with an extreme or excessive enthusiasm for something, especially a religion, or religious issues.

Thesaurus: enthusiast, devotee, zealot, addict, freak (slang), fiend (slang); extremist, activist.

adj

1. fanatical.

Derivative: fanaticism
noun

Etymology: 16c: from Latin fanaticus filled with a god or frenzied.