expression, godan verb (-ru)
thunder rumbles; thunder roars
Describes the natural phenomenon of thunder sounding. Often used in weather descriptions or to express sudden loud noise.
遠くで雷が鳴っている。
Thunder is rumbling in the distance.
急に雷が鳴り始めた。
Suddenly, thunder began to rumble.
Compound of 雷 (thunder) + が (subject marker) + 鳴る (to sound). A straightforward literal expression.