The most common and most likely answer to this crossword clue is the 10 letter word ASTRONOMER
I've seen this crossword clue in The Daily Telegraph
A
S
T
R
O
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More clues leading to the result ASTRONOMER
- Scientist and epicure missing grand opening of restaurant
- American embraces endlessly resilient old scientist
- Scientist who may have difficulty working under a cloud
- More on star from me?
- Monroe’s art excited one looking up to stars
- He dissects star and moon with both ends of radio telescope
- One watching Sky on stream or off
- Moon starer, possibly
- Rarest moon moving for one?
- Bliss, maybe of troubled star Monroe
Buddy explains!
The straight part
We know that "Night-watchman" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case night-watchman = astronomer.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 ASTRONOMER mean?
ASTRONOMER noun- One who studies astronomy, the stars or the physical universe; a scientist whose area of research is astronomy or astrophysics