boom in WordNet English dictionary

1. hit hard
   "He smashed a 3-run homer"
   smash  nail  boom  blast 
   
2. grow vigorously
   "The deer population in this town is thriving"; "business is booming"
   boom  thrive  flourish  expand 
   
3. make a resonant sound, like artillery
   "His deep voice boomed through the hall"
   boom  din 
   
4. make a deep hollow sound
   "Her voice booms out the words of the song"
   boom  boom out 
   
5. be the case that thunder is being heard
   "Whenever it thunders, my dog crawls under the bed"
   thunder  boom 
   

1. a sudden happening that brings good fortune (as a sudden opportunity to make money)
   "the demand for testing has created a boom for those unregulated laboratories where boxes of specimen jars are processed like an assembly line"
   boom  bonanza  gold rush  gravy  godsend  manna from heaven  windfall  bunce 
   
2. any of various more-or-less horizontal spars or poles used to extend the foot of a sail or for handling cargo or in mooring
   boom 
   
3. a pole carrying an overhead microphone projected over a film or tv set
   boom  microphone boom 
   
4. a deep prolonged loud noise
   boom  roar  roaring  thunder 
   
5. a state of economic prosperity
   boom