wildfire

American  

[wahyld-fahy^uhr] / ˈwaɪldˌfaɪər /

noun

1. any large fire in brush, forests, or open spaces that spreads rapidly and is hard to extinguish.

2. a highly flammable composition, such as Greek fire, difficult to extinguish when ignited, formerly used in warfare.

3. sheet lightning, unaccompanied by thunder.

4. the ignis fatuus or a similar light.

5. Plant Pathology. a disease of tobacco and soybeans, characterized by brown, necrotic spots, each surrounded by a yellow band, on the leaves and caused by the bacterium Pseudomonas tabaci.

6. Pathology Obsolete. erysipelas or some similar disease.

---

wildfire British  

/ ˈwaɪldˌfaɪə /

noun

1. a highly flammable material, such as Greek fire, formerly used in warfare

2. 1. a raging and uncontrollable fire

   2. anything that is disseminated quickly (esp in the phrase spread like wildfire )

3. lightning without audible thunder

4. another name for will-o'-the-wisp

---

wildfire Idioms  

1. see spread like wildfire.

---

Etymology

Origin of wildfire

First recorded before 1000; Middle English wildefire, Old English wildfȳr; equivalent to wild + fire

Explanation

A wildfire is an uncontrolled blaze, especially one that ignites rural areas with a lot of trees and dry brush. Factors like drought, unusually warm weather, and development can contribute to bigger wildfires. Wildfires are a natural part of many forest lifecycles, but human activity and climate change have made these conflagrations more frequent and dangerous. Unextinguished campfires, lightning strikes, and power lines can all ignite a fire that spreads and becomes a wildfire, given dry enough conditions. The biggest U.S. wildfire, which burned acres of the Santa Fe National Forest in New Mexico, devastated an area larger than New York City. In Old English, a wildfire was a wilde fyr.

Example Sentences

Runoff from wildfire burn areas or bacteria such as E. coli could enter sinkholes connected to Roaring Springs Cave and reach the water supply.

From Science Daily • Jun. 2, 2026

Earlier this year curlew eggs were saved by firefighters during a "significant wildfire" in County Fermanagh as their nest was directly in the fire's path and close to being lost in the blaze.

From BBC • May 31, 2026

Previous work from Lipton's laboratory has shown that this process can be triggered by factors such as aging, inflammation and environmental exposures including air pollution and wildfire smoke.

From Science Daily • May 31, 2026

As for the federal government, independent analyses by Grassroots Wildland Firefighters and NPR found that Forest Service wildfire mitigation work is on the decline amid federal staffing cuts.

From Los Angeles Times • May 30, 2026

“There’s a wildfire down the other side of the mountain!”

From "Two Degrees" by Alan Gratz

Related Words

• blaze
• conflagration
• flare
• flash
• light
• spark