A volcanic rock.

Of or pertaining to a volcano or volcanoes / Produced by a volcano, or, more generally, by igneous agencies / Changed or affected by the heat of a volcano.

plural of volcanic

The quality or state of being volcanic. / The level of power of a volcano.

By means of a volcano. / (figuratively) In a volcanic (explosive) manner.

plural of volcanicity

volcanic

Archaic form of volcano.

(volcanology) Any of the natural phenomena and processes associated with the action of volcanos, geysers and fumaroles

(transitive) To expose to volcanic heat.