The most common and most likely answer to this crossword clue is the 6 letter word KABOOM
I've seen this crossword clue in Financial Times
K
A
B
O
O
M
Buddy explains!
The straight part
We know that "Sound of explosion" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sound of explosion = kaboom.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does KABOOM mean?
KABOOM noun- The sound of an explosion, typically seen in comic strips or heard in a light-hearted conversation.
- The sound of an explosion, typically seen in comic strips or heard in a light-hearted conversation.