volcanic

/vɑlˈkænɪk/

/vɒlˈkænɪk/

If something is volcanic, it's violently explosive, like the volcanic eruption from a mountain or a two-year-old's volcanic temper tantrum after skipping his afternoon nap.

Use this adjective to describe anything related to volcanoes, like volcanic ash and rock left behind after a volcanic eruption, or the volcanic activity picked up by a scientist's equipment. It's also a great way to talk about emotions that are (figuratively, at least) as volatile as a volcano. If your sister's mood is volcanic, you'll want to steer clear of her. The source of both volcanic and volcano is the Roman god of fire, Vulcan.

Definitions of volcanic

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”
2. adjective

   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”

   synonyms:

   extrusive

   of rock material; forced out while molten through cracks in the earth's surface
3. adjective

   explosively unstable
   “a volcanic temper”

   synonyms:

   unstable

   lacking stability or fixity or firmness