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

• time bomb
• powder keg
• flash point

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

Early Sunday on the same sparsely populated peninsula, the Krasheninnikov volcano spewed white ash clouds into the sky for the first time in hundreds of years. —Callum Sutherland, Time, 2 Oct. 2025

The Philippines sits along the Ring of Fire, a 25,000-mile (40,000-kilometer) arc of seismic fault lines around the Pacific Ocean that hosts more than half of the world’s volcanoes. —Brandon Miller, CNN Money, 30 Sep. 2025

Throughout the course, climbers can see the 2,303-foot-high Triumvirate Glacier, with all its moraines and otherworldly blue crevasses, as well as the Tordrillo Mountains, which include Mount Spurr, an active volcano that last erupted in 1992. —AFAR Media, 30 Sep. 2025

When the volcano erupts, Mario and Dani have to navigate its danger and their sentiments for each other. —John Hopewell, Variety, 30 Sep. 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.