thunder definition

1. a booming or crashing noise caused by air expanding along the path of a bolt of lightning
2. move fast, noisily, and heavily
• examples: The bus thundered down the road
3. utter words loudly and forcefully
• examples: `Get out of here,' he roared
4. be the case that thunder is being heard
• examples: Whenever it thunders, my dog crawls under the bed
5. to make or produce a loud noise
• examples: The river thundered below
• examples: The engine roared as the driver pushed the car to full throttle