1.a deep prolonged loud noise
2.a state of economic prosperity
3.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 lik an assembly line
4.a pole carrying an overhead microphone projected over a film or tv set
5.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
1.make a resonant sound, like artillery;
His deep voice boomed through the hall
2.hit hard;
He smashed a 3-run homer
3.be the case that thunder is being heard;
Whenever it thunders, my dog crawls under the bed
4.make a deep hollow sound;
Her voice booms out the words of the song
5.grow stronger;
The economy was booming