There are 22 words that start with 'boom'.
| boom | booms | boomy | 
| boomed | boomer | boombox | 
| boomers | boomier | booming | 
| boomkin | boomlet | boomiest | 
| boomkins | boomlets | boomtown | 
| boomboxes | boomerang | boomingly | 
| boomtowns | boomerangs | boomeranged | 
| boomeranging | ||
Note: These 22 words that start with 'boom' are found from the USA & Canada version of the tournament Scrabble word list.