The most common and most likely answer to this crossword clue is the 8 letter word INFRINGE
I've seen this crossword clue in Independent
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N
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E
More clues leading to the result INFRINGE
- Break in regularly after pinching item of jewellery
- Break with trendy element of festival entertainment
- In front of family circle, uncle’s last to trespass
- Violate popular part of Edinburgh Festival
- Cross the line and briefly gather round circle
- Break popular with those on edge
- Neglect to obey popular call to invade the borders of France
- Encroach on one northern border
- Break where some locks have been cut
- To trespass in firing range with government artillery leaving, that’s wrong
Buddy explains!

The straight part
We know that "cross the line" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case cross the line = infringe.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 INFRINGE mean?
INFRINGE verb- Break or violate a treaty, a law, a right etc.
- Break in or encroach on something.