The most common and most likely answer to this crossword clue is the 7 letter word PERIGEE
I've seen this crossword clue in The Guardian
P
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More clues leading to the result PERIGEE
Buddy explains!
The straight part
We know that "where moon is nearest to us" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case where moon is nearest to us = perigee.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 PERIGEE mean?
PERIGEE noun- The point, in an orbit about the Earth, that is closest to the Earth: the periapsis of an Earth orbiter.
- (more generally) The point, in an orbit about any planet, that is closest to the planet: the periapsis of any satellite.
- (possibly obsolete outside astrology) The point, in any trajectory of an object in space, where it is closest to the Earth.