Of or pertaining to a volcano or volcanoes; as, volcanic heat.

Produced by a volcano, or, more generally, by igneous agencies; as, volcanic tufa.

Of, pertaining to, like, or characteristic of a volcano; characterized by or composed of volcanoes; produced, influenced, or changed by a volcano or by volcanic agencies; made of materials derived from volcanoes.

A variety of igneous rock which is fine grained or glassy due to rapid cooling upon or near the surface of the earth.