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 of volcano

• 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

The rum is housed in a bespoke crystal decanter designed to evoke the ridges and peaks of the San Cristóbal volcano; it’s topped with a stopper made from volcanic obsidian rock, with a leather band adorning the neck. —Robb Report Studio, Robb Report, 13 Nov. 2025

In 1985 the Nevado del Ruiz volcano triggered a mudslide that wiped out the town of Armero, Colombia in one of the 20th century’s worst natural disasters. —Greg Dixon, NPR, 13 Nov. 2025

Io, the volcanic death-world Jupiter’s moon Io is arguably the most geologically active body in the Solar System, with over 400 active volcanoes, lava flows hundreds of kilometres long, and a surface coated in sulfur and sulfur dioxide. —Kaif Shaikh, Interesting Engineering, 13 Nov. 2025

The volcano spewed so much lava that flows covered up to 80% of the floor of the Halemaʻumaʻu crater, the USGS said. —Julia Jacobo, ABC News, 10 Nov. 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.