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volcano

American  
[vol-key-noh] / vɒlˈkeɪ noʊ /

noun

plural

volcanoes, volcanos

  1. a vent in the earth's crust through which lava, steam, ashes, etc., are expelled, either continuously or at irregular intervals.

  2. a mountain or hill, usually having a cuplike crater at the summit, formed around such a vent from the ash and lava expelled through it.

volcano British  
/ vɒlˈkeɪnəʊ /

noun

  1. an opening in the earth's crust from which molten lava, rock fragments, ashes, dust, and gases are ejected from below the earth's surface

  2. a mountain formed from volcanic material ejected from a vent in a central crater

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
volcano Scientific  
/ vŏl-kā′nō /

  1. An opening in the Earth's crust from which lava, ash, and hot gases flow or are ejected during an eruption.

  2. A usually cone-shaped mountain formed by the materials issuing from such an opening. Volcanoes are usually associated with plate boundaries but can also occur within the interior areas of a tectonic plate. Their shape is directly related to the type of magma that flows from them—the more viscous the magma, the steeper the sides of the volcano.

  3. ◆ A volcano composed of gently sloping sheets of basaltic lava from successive volcanic eruptions is called a shield volcano. The lava flows associated with shield volcanos, such as Mauna Loa, on Hawaii, are very fluid.

  4. ◆ A volcano composed of steep, alternating layers of lava and pyroclastic materials, including ash, is called a stratovolcano. Stratovolcanos are associated with relatively viscous lava and with explosive eruptions. They are the most common form of large continental volcanos. Mount Vesuvius, Mount Fuji, and Mount St. Helens are stratovolcanos.

  5. Also called composite volcano

  6. See more at hot spot island arc tectonic boundary volcanic arc

volcano Cultural  

  1. A cone-shaped mountain or hill created by molten material that rises from the interior of the Earth to the surface.

Discover More

Volcanoes tend to occur along the edges of tectonic plates.

Eruptions and lava flows associated with them can be very destructive. (See Mount Saint Helens and Mount Vesuvius.)

Etymology

Origin of volcano

1605–15; < Italian < Latin Volcānus, variant of Vulcānus Vulcan

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

So when rain drenches Tenerife's beaches it is not unusual for snow to fall over the volcano.

From BBC • Mar. 20, 2026

Another feature of Storm Therese has been snow, which has fallen over high ground surrounding Mount Teide - the volcano in the centre of Tenerife.

From BBC • Mar. 20, 2026

However, those alerts still detected magma movements beneath the volcano.

From Science Daily • Mar. 15, 2026

An Indonesian volcano led to lousy weather in Europe.

From The Wall Street Journal • Mar. 6, 2026

Don Swanson spent his first hours at Mount St. Helens leaning out of a hovering helicopter directly over the summit of the volcano.

From "Mountain of Fire" by Rebecca E. F. Barone

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.