volcano

noun

vol·​ca·​no väl-ˈkā-(ˌ)nō 

vȯl-

plural volcanoes or volcanos

1

: a vent in the crust of the earth or another planet or a moon from which usually molten or hot rock and steam issue

also : a hill or mountain composed wholly or in part of the ejected material

2

: something of explosively violent potential

Illustration of volcano

• 1 cinder cone
• 2 shield volcano
• 3 stratovolcano

Synonyms

• flash point
• powder keg
• time bomb
• tinderbox

Examples of volcano in a Sentence

The volcano last erupted 25 years ago.

after months of tension the roommates' living situation was a volcano

Recent Examples on the Web

One of the world's most active volcanoes, Kilauea on Hawaii's Big Island, began spewing lava from the north vent Wednesday, the latest event in an ongoing eruption that began almost six months ago. —CBS News, 12 June 2025

In the depths of the Mid-Atlantic Ridge, underwater volcanoes spew material into the ocean water. —Irene Wright, Miami Herald, 11 June 2025

Among the benefits of the volcano: fertile farmland and tourism. —Colleen Barry, Los Angeles Times, 3 June 2025

The soaring ash rose to form a mushroom cloud high above Etna, Europe's highest active volcano, triggering a red alert for aviation crews in the region. —Bill Chappell, NPR, 2 June 2025

Word History

Etymology

Italian or Spanish; Italian vulcano, from Spanish volcán, ultimately from Latin Volcanus Vulcan

First Known Use

1665, in the meaning defined at sense 1

Phrases Containing volcano

• shield volcano

Kids Definition

volcano

noun

vol·​ca·​no väl-ˈkā-nō 

vȯl-

plural volcanoes or volcanos

: a vent in the earth's crust from which melted or hot rock and steam come out

also : a hill or mountain composed entirely or in part of the material thrown out

Etymology

from Italian or Spanish; Italian vulcano "volcano," from Spanish vulcán, from Latin Volcanus, Vulcanus "Vulcan (Roman god of fire)"

Word Origin

The ancient Greeks and Romans had many gods and goddesses. Each of these deities was in charge of a special kind of work or an aspect of nature. Many of the happenings in nature were explained in myth as the actions of one or more of these gods or goddesses. The Roman god of fire was known as Vulcanus in Latin (Vulcan in English). He was thought to live inside Mount Etna, a volcano on the island of Sicily. Vulcan was a giant who worked as a blacksmith, forging the thunderbolts for Jupiter, king of the gods. The smoke and occasional fiery rocks and lava that came from Mount Etna were thought to be from Vulcan's forge. That is how his name came to be applied to a mountain that sometimes spews forth fire and smoke.