The most common and most likely answer to this crossword clue is the 3 plus 4 letter word AIR RAID
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More clues leading to the result AIR RAID
Buddy explains!

The straight part
We know that "bombing" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case bombing = air raid.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 AIR RAID mean?
AIR RAID noun- An attack on a surface target by aircraft.
- A passing-heavy offensive scheme based on a shotgun formation with four wide receivers and a single running back.