Thunderous describes a sound so loud and deep it reminds you of thunder rumbling across the sky during a storm. When the crowd gives thunderous applause after an amazing performance, the clapping fills the whole auditorium with a powerful, rolling noise that seems to shake the air. When a herd of elephants runs across the African savanna, their footsteps create a thunderous rumble that can be felt through the ground.

The word captures both volume and a particular quality: thunderous sounds are deep and booming, with a weight and power behind them. A whistle can be loud, but it's not thunderous. A thunderous sound has bass and resonance, like when a massive wave crashes against rocks or when thousands of fans stomp their feet in a stadium.

You might read about a thunderous voice booming across a battlefield, or a thunderous crash when something heavy falls. The word suggests not just noise, but impressive, attention-commanding power. When something is thunderous, everyone stops and notices.