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

Excellent guide/driver combos take guests off-roading on geological Big 5 safari drives to see salt flats, geysers at 14,000 feet, canyons and dunes that rival Jordan and Utah, and a string of volcanoes that make this part of Chile one of the most active sites in the world. —Laura Dannen Redman, Robb Report, 28 July 2025

Iceland Iceland offers one of the most photogenic landscapes on Earth — including waterfalls, volcanoes and geothermal spas — and boasts the longest totality on land, at 2 minutes, 13.7 seconds. —Jamie Carter, Space.com, 21 July 2025

Seafloor volcanoes could heat these moons’ oceans and provide the basic chemicals needed for life. —James F. Holden, The Conversation, 21 July 2025

When glaciers shrink, volcanoes stir, and that may be just the beginning of a dangerous cycle. —Pranjal Malewar, New Atlas, 11 July 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.