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

The main islands, including Hawaii, Maui, Lanai, Oahu and Kauai, are among a chain of islands, atolls, reefs and volcanoes beneath the sea that stretches 1,700 miles in the Pacific Ocean. —Dinah Voyles Pulver, USA Today, 11 Sep. 2025

In Arenal, families can soak in natural hot springs and go zip-lining in the shadow of an epic volcano. —Travel + Leisure Editors, Travel + Leisure, 9 Sep. 2025

But now European and American scientists are exploring whether the first human Martians could find refuge via dormant volcanos scattered across the Red Planet, inside lava tubes that criss-cross the Mars underground. —Kevin Holden Platt, Forbes.com, 9 Sep. 2025

Lighthouse station California’s Central Coast may no longer have active volcanoes, but there is plenty of evidence of ancient volcanic activity, from plugs like Morro Rock (the hardened interior of a former volcano) to stacks (islands formed from eroded volcanic rock). —A.k. Whitney, Oc Register, 9 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.