The most common and most likely answer to this crossword clue is the 4 plus 5 letter word RING FENCE
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More clues leading to the result RING FENCE
Buddy explains!
The straight part
We know that "comprehensive barrier" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case comprehensive barrier = ring fence.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 RING FENCE mean?
RING FENCE verb- To guarantee the safety of funds or investment. In particular, to ensure some degree of distinction for monies, that may provide immunity against untoward financial claims.
- To specify that funds may only be used for a specific purpose, especially government funds.
- To require workers to remain in (particular types of work), as during wartime.