1. (

• boom ,
• din

) make a resonant sound, like artillery; "His deep voice boomed through the hall" ;

2. (

• smash ,
• nail ,
• boom ,
• blast

) hit hard; "He smashed a 3-run homer" ;

3. (

• thunder ,
• boom

) be the case that thunder is being heard; "Whenever it thunders, my dog crawls under the bed" ;

4. (

• boom ,
• boom_out

) make a deep hollow sound; "Her voice booms out the words of the song" ;

5. (

• boom ,
• thrive ,
• flourish ,
• expand ,

) grow vigorously; "The deer population in this town is thriving"; "business is booming" ;