volcanic

Where it comes from

Volcanic was formed from volcano and -ic. English volcano came from Italian volcano, ultimately from Latin Volcanus or Vulcanus, the name of Vulcan, the Roman god associated with fire and metalworking.

How the meaning developed

A divine name became the ordinary name for a geological vent, then produced volcanic for what comes from or resembles one. The physical violence of eruptions also gave volcanic its figurative sense: suddenly and explosively violent, as in a volcanic temper.