maniac

Greek μανία was not limited to clinical madness: it could describe the inspired frenzy of a prophet, the fury of a lover, or the energy of someone seized by an overwhelming passion. Greek writers connected it with words for raging, spirit, and even the seer mantis, though the deeper family resemblance is uncertain rather than proven. Latin carried mania into medical language, and French turned it into maniaque before English borrowed maniac around 1600. At first, maniac was an adjective—someone could be “maniac” in the sense of raving or mentally deranged—while the noun meaning “a mad person” arrived by 1763. The suffix -ac is doing quiet grammatical work: it turns “mania” into “one characterized by mania,” much as cardiac means “related to the heart.” Today the word can describe a dangerous person, an obsessive enthusiast, or even a Dance Dance Revolution expert—proof that an ancient word for divine frenzy can end up cheering from an arcade floor.