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

A series of wildfire warnings have been issued for Scotland.

From BBC • Apr. 23, 2026

A bill that would have required insurers to offer coverage to homeowners who take steps to reduce wildfire risk on their property died in the Legislature.

From Los Angeles Times • Apr. 23, 2026

But with warm weather and wildfire season ahead, community leaders would prefer to see a full reservoir even if the water isn’t suitable for drinking.

From Los Angeles Times • Apr. 22, 2026

A Nigerian scientist's "personal experience" with a wildfire, its threat to endangered bats she discovered just days before, and her campaign to protect them, has won her the global Goldman Environmental Prize.

From BBC • Apr. 20, 2026

Among the middle-class and black professional community of southeastern Virginia, however, word traveled like wildfire: Mrs. Vaughans office is hiring.

From "Hidden Figures" by Margot Lee Shetterly

Related Words

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