fire-eater

The compound noun 'fire-eater' is a transparent English formation. Its literal sense, dating to the late 18th century, directly describes a circus or street performer whose act involves putting flaming objects into their mouth, creating the illusion of consuming fire. The metaphorical sense, recorded from the early 19th century, leverages the shocking and dangerous nature of the literal act to characterize a person with a fiercely combative, argumentative, or aggressively zealous temperament. Thus, the word's logic moves from a literal description of a physical spectacle to a figurative label for a pugnacious personality.

Structure: fire (combustion) + eater (one who consumes) fire: Old English; noun; the phenomenon of combustion manifested as light, flame, and heat. eater: English; agent noun suffix; derived from the verb 'eat' + the agentive suffix '-er', meaning 'one who eats or consumes'.