The most common and most likely answer to this crossword clue is the 7 letter word SEIZURE
I've seen this crossword clue in The Guardian
S
E
I
Z
U
R
E
More clues leading to the result SEIZURE
- Game over during the sixteenth French attack
- Attack decapitated blue whale first
- Certain to assimilate East Indian Zone in attack
- Attack and capture
- Capture by sudden attack
- Picked up, spots United on attack
- Following opponents, gun raised on sudden attack
- Fit Aznavour’s final couplet into French number seen here
- Fit for occupation
- You are caught by sixteen in France in sudden attack
Buddy explains!

The straight part
We know that "Capture /Capture/sudden attack/sudden attack" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case capture /capture/sudden attack/sudden attack = seizure.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 SEIZURE mean?
SEIZURE noun- The act of taking possession, as by force or right of law.
- A sudden attack or convulsion, (e.g. an epileptic seizure).
- A sudden onset of pain or emotion.
- That which is seized, or taken possession of; a thing laid hold of, or possessed.
- Retention within one's grasp or power; possession; ownership.