extremely hot; "the fervent heat...merely communicated a genial warmth to their half-torpid systems"- Nathaniel Hawthorne; "set out...when the fervid heat subsides"- Frances Trollope
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"
explosively unstable; "a volcanic temper"
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"