The most common and most likely answer to this crossword clue is the 7 letter word POLICED
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More clues leading to the result POLICED
Buddy explains!

The straight part
We know that "Monitored" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case monitored = policed.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 POLICED mean?
POLICED verb- To enforce the law and keep order among (a group).
- To clean up an area.
- To enforce norms or standards upon.