wildfire
/ˈwʌɪl(d)fʌɪə
/noun
1A large, destructive fire that spreads quickly over woodland or brush.Prolonged dry periods and seasonal high winds in spring help create ideal conditions for wildfire to spread quickly through highly-flammable moorland undergrowth....
- The wildfire quickly spreads, consuming the thick, dried-out vegetation and almost everything else in its path.
- More and more western communities surrounded by forests are responding to the threat of destructive wildfire with a wide range of economic and policy changes.
2 [mass noun] historical A combustible liquid such as Greek fire that was readily ignited and difficult to extinguish, used especially in warfare.Aegon bellowed as he poured wildfire on Stokeworth.
3 less common term for will-o'-the-wisp.The moving lights which are called ball lightning when they occur indoors become wildfire or will-o'-the-wisps in the open air.
Phrases
spread like wildfire