Yes, boom is a Scrabble word!
...and is worth 8 points in Scrabble, and 10 points in Words with Friends
boom
Verb
1. Make a resonant sound, like artillery
2. Hit hard
3. Be the case that thunder is being heard
4. Make a deep hollow sound
5. Grow vigorously
Noun
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)
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
What Scrabble words can I make with the letters in boom?
3 Letter Words
2 Letter Words