Plural of “volcano”

The plural of volcano is volcanoes (some dictionaries also accept volcanos).

Why

"Volcano" comes from Italian, ultimately from Vulcan, the Roman god of fire and metalworking, whose forge was said to lie beneath Mount Etna and other volcanic islands. English borrowed the word in the 17th century, and it followed the common older pattern of adding -es to consonant-plus-o nouns, giving the traditional "volcanoes." Vulcano, one of the Aeolian Islands off the coast of Sicily, gave the Roman god and the geological feature both their shared name, since ancient observers believed its periodic eruptions were direct evidence of the god's underground forge at work.

"Volcanoes" remains dominant, especially in geology and general reference writing, but "volcanos" has become common enough in casual and journalistic writing that most major dictionaries now list it as an accepted variant rather than an error — one of relatively few -oes words where the shorter, regularized spelling has gained real, dictionary-sanctioned ground.

Usage note

"Volcanoes" is the safer, more traditional choice for formal, scientific, or educational writing. "Volcanos" appears often enough in general and news writing that it won't read as wrong to most audiences, but style guides for academic geology still generally prefer the -oes spelling.

Geologists classify volcanoes into several distinct structural types, shield volcanoes, stratovolcanoes, and cinder cones among them, based on eruption style and the shape the built-up lava and ash eventually take, though all these types take the identical plural regardless of their structural differences. The word's connection to Vulcan reflects a broader Roman and Greek tendency to explain dramatic natural phenomena through mythology, treating volcanic activity as evidence of divine forge-work happening deep underground rather than as the geological process of magma reaching the surface that we understand it as today.

Common real mistakes

There's no real error here so much as a live spelling variation, and the actual mistake editors flag is a document that opens with "volcanoes" in paragraph one and drifts into "volcanos" by paragraph three, which reads as inattentive proofreading rather than a deliberate style choice. Writers should also distinguish "volcano" (the landform itself) from "eruption" (the event), since a single volcano can produce many separate eruptions over its lifetime, a distinction that matters in careful geological writing.

The wider pattern

"Volcano" belongs to a subgroup of -o nouns, alongside "mosquito" and "tornado," where the traditional -oes plural remains more common and more formal, but a regularized -os spelling has gained real, dictionary-recognized acceptance rather than staying a fringe misspelling the way "echos" or "vetos" have.

Examples

• The island chain formed from a series of underwater volcanoes.
• Several volcanoes in the region remain active today.
• Geologists monitor volcanoes for signs of eruption.
• The documentary followed scientists studying volcanoes across three continents.
• Ancient civilizations built settlements near fertile volcanic soil despite the risk from nearby volcanoes.
• Ash from the volcanoes darkened the sky for days.
• The park protects a chain of dormant volcanoes.
• Ring of Fire volcanoes account for most of the world's eruptions.
• Researchers used satellite imagery to track changes in the volcanoes.
• Local legends describe the volcanoes as sleeping giants.
• The expedition mapped three dormant volcanoes along the ridge.
• Farmers cultivated the fertile slopes near the volcanoes.
• The museum diorama depicted ancient volcanoes erupting.
• The tour guide explained how the volcanoes shaped the coastline.
• Seismographs recorded tremors beneath both volcanoes overnight.
• The islands formed as volcanoes rose from the seafloor.
• Scientists installed sensors on the two active volcanoes.
• The eruption reshaped the landscape around both volcanoes.
• The two volcanoes last erupted centuries apart.
• Ash clouds from the volcanoes disrupted regional flights.
• Local guides lead hikes up both volcanoes each summer.
• Both volcanoes are monitored continuously for seismic activity.
• Farmers rebuilt near the volcanoes despite the risk.