1. A deep prolonged loud noise
   "The thunder of the explosion could be heard for miles";
   - boom, roar, roaring
    
2. A booming or crashing noise caused by air expanding along the path of a bolt of lightning
   "The rumble of thunder in the distance warned of an approaching storm"
    
3. [slang] A street name for heroin
   "The police were investigating dealers selling thunder in the neighbourhood";
   - big H [slang], hell dust [slang], nose drops [slang], smack [slang], skag [slang], scag [slang]

1. Be the case that thunder is being heard
   "Whenever it thunders, my dog crawls under the bed";
   - boom
    
2. To make or produce a loud noise
   "The river thundered below"
    
3. Utter words loudly and forcefully
   "'Get out of here,' he thundered";
   - roar
    
4. Move fast, noisily, and heavily
   "The bus thundered down the road"

Derived forms: thundering, thundered, thunders

Type of: diacetylmorphine, diamorphine, heroin, howl, junk [informal], move, noise, roar, shout, sound

Encyclopedia: Thunder, Lightning and Sunshine