volcanic

adjective

1. relating to or produced by or consisting of volcanoes

- volcanic steam

- volcanic islands such as Iceland

- a volcanic cone is a conical mountain or hill built up of material from volcanic eruptions

2. explosively unstable

- a volcanic temper

Similar word(s): unstable

3. igneous rock produced by eruption and solidified on or near the earth's surface; rhyolite or andesite or basalt

- volcanic rock includes the volcanic glass obsidian

Similar word(s): extrusive