1. [ adjective ] 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"

Related terms: volcano
2. [ adjective ] explosively unstable

"a volcanic temper"

Related terms: unstable
3. [ adjective ] (geology) igneous rock produced by eruption and solidified on or near the earth's surface; rhyolite or andesite or basalt
Synonyms: eruptive

"volcanic rock includes the volcanic glass obsidian"

Related terms: extrusive
Similar spelling:   volcanism