Volcanic

volcanic or volcano or volcanism or volcanize or volcanology, etc.
(each of these words may also be spelled with vul-): The Roman god Vulcan, identified with the Greek Hephaestus, was the supreme craftsman of the gods. His helpers were three Cyclopes and his forge was located in various places, but most often under Mt. Etna in Sicily, or similar volcanic regions, which betray its presence. A volcano is a vent in the earth's crust, which spews forth molten material and thereby forms a mountain. Volcanism or Vulcanism refers to any volcanic force or activity. To volcanize is to subject a substance, especially rubber, to such extremes of heat that it undergoes a change and thereby becomes strengthened. Volcanology is the scientific study of volcanic phenomena.