The most common and most likely answer to this crossword clue is the 10 letter word DETONATION
I've seen this crossword clue in Financial Times
D
E
T
O
N
A
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N
More clues leading to the result DETONATION
Buddy explains!
The straight part
We know that "blast" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case blast = detonation.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 DETONATION mean?
DETONATION noun- An explosion or sudden report made by the near-instantaneous decomposition or combustion of unstable substances. Specifically, combustion that spreads supersonically via shock compression.
- Engine knocking, an improper combustion in internal combustion engines