A fireball is a bright ball of flame that appears in the sky. You might see one when there's a massive explosion or accident.
When we talk about fireballs, we usually mean big balls of fire that appear after something has exploded or burned intensely. For example, if a plane crashes and it's still burning on impact, you could see a fireball rising from the wreckage. Sometimes, people even use "fireball" to describe a meteor or a shooting star - these are small pieces of rock from space that burn up in the atmosphere and look like bright balls of light for a second. In science fiction movies or games, fireballs can be used as a powerful attack, where a character shoots a big ball of flame at their enemies.
A ball of fire, especially one associated with an explosion.
To explode in a ball of flame.
Example: The car swerved off a road, hit a wall, and fireballed as the petrol tank exploded.
