The most common and most likely answer to this crossword clue is the 9 letter word GREENWICH
I've seen this crossword clue in The Guardian
G
R
E
E
N
W
I
C
H
More clues leading to the result GREENWICH
- Riotous cheering around Western part of London
- Fresh crank’s dismissed new London borough
- Novice hag wasting time where it’s monitored?
- No degrees at this London university?
- Time and place
- Excited cheering as point is secured by Arsenal’s neighbour
- Discordant cheering going round West London borough
- Inexperienced magician with no time for London Town
Buddy explains!

The straight part
We know that "where it’s monitored?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case where it’s monitored? = greenwich.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.