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

Vulcano About an hour ferry ride from Milazzo, Vulcano lures visitors with its active volcano, Gran Cratere, and open-air mud baths just steps from the port, where bathers slather on the mineral-rich goodness before rinsing in the sea. —Nicky Swallow, Travel + Leisure, 17 May 2026

The flooding is the latest crisis for Hawaii’s farmers, on top of wildfires, pests and volcanic tephra — ash and debris ejected by an erupting Big Island volcano, said the state’s top agriculture official, Sharon Hurd. —Jennifer Sinco Kelleher, Los Angeles Times, 17 May 2026

Here is another wooden lamp, but one inspired by volcanoes. —Anthony Paletta, Curbed, 17 May 2026

The main residence opens toward panoramic views of the Irazú and Barva volcanoes, while a separate three-bedroom guesthouse includes its own office space. —Natalie Hoberman, Forbes.com, 16 May 2026

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.