The roar of a motorbike.
An example of a roar is the sound of thunder.
The engines roared.
The truck roared down the road.
The crowd roared itself hoarse.
To roar oneself hoarse.
The audience roared at his jokes.
The lioness roared to scare off the hyenas.
An example of roar is to laugh deeply and heartily.
An example of roar is the combined sound of many people talking.