volcanic

adj

1. (not-comparable)Of or pertaining to a volcano or volcanoes.

   “volcanic heat”

   “volcanic activity”

   “Some 200 million years ago, the rocks that became the Palisades cliffs just across the Hudson River from Manhattan formed during volcanic activity that helped rip apart the ancient supercontinent Pangea. That volcanism helped lead to the birth of the Atlantic Ocean while it also contributed to killing off as much as a quarter of all life on Earth during the event known as the end-Triassic mass extinction.”

2. (not-comparable)Produced by a volcano, or, more generally, by igneous agencies.

   “volcanic tufa”

   “volcanic ash”

3. (not-comparable)Changed or affected by the heat of a volcano.
4. (figuratively, not-comparable)Reminiscent of a volcano; explosive, violent, full of suppressed anger, energy etc.

   “Jo rose indignified, Vanessa following in her volcanic wake.”

   “With that the system was complete, and ready to have its disastrous effect on Martin Luther's volcanic temper.”

noun

1. A volcanic rock.

   “The Ellesmere Island Volcanics are a Late Cretaceous volcanic group of volcanoes and lava flows in the Qikiqtaaluk Region of northern Ellesmere Island, Nunavut, Canada.”