The most common and most likely answer to this crossword clue is the 7 plus 8 letter word MOLOTOV COCKTAIL
M
O
L
O
T
O
V
C
O
C
K
T
A
I
L
More clues leading to the result MOLOTOV COCKTAIL
Buddy explains!
The straight part
We know that "Explosive" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case explosive = molotov cocktail.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.