球状闪电

Fireball \Fire"ball`\, n.
1. (Mil.) A ball filled with powder or other combustibles,
intended to be thrown among enemies, and to injure by
explosion; also, to set fire to their works and light them
up, so that movements may be seen.

2. A rare phenomenon often associated with or caused by
lightning, resembling a luminous ball of fire passing
rapidly through the air or along solid objects, then
disappearing, and sometimes exploding. It seldom lasts
more than a few seconds. Also called {ball lightning},
{globe lightning}, {globular lightning}, or {kugelblitz}.
[Webster 1913 Suppl. +PJC]

3. A large mass of fire caused by a large explosion, as of
inflammable liquids or a nuclear device. The larger
fireballs, as of nuclear explosions, rise seemingly intact
into the air and may reach high altitudes while still
glowing.
[PJC]