Definition of boom
intransitive verb
1
:to make a deep hollow sound
2 a
:to increase in importance, popularity, or esteem
b
:to experience a sudden rapid growth and expansion usually with an increase in prices
- business was booming
c
:to develop rapidly in population and importance
- California boomed when gold was discovered there
d
:to increase greatly in size or number
- the population boomed
transitive verb
1
:to cause to resound
—often used with out
- his voice booms out the lyrics
2
:to cause a rapid growth or increase of :boost
3
:to hit or kick forcefully
- boom a punt
