The most common and most likely answer to this crossword clue is the 4 letter word MOON
M
O
O
N
More clues leading to the result MOON
- Display behind Low cartoon, at the back
- Display behind Medical Officer, working
- Night light activated after flash
- Second working satellite around the earth
- Low northern celestial body
- Heavenly body, low by noon
- Night light to display behind dish briefly
- Satellite’s second leg
- In one short day starter in office is to show a lot of cheek
- Heavenly body exemplified in Titania? Show Bottom!
Buddy explains!

The straight part
We know that "Heavenly body" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case heavenly body = moon.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 MOON mean?
MOON proper noun- The Earth's moon Luna; the sole natural satellite of the Earth, represented in astronomy and astrology by ☾.
- The god of the Moon in Heathenry.
- A surname.
- The 54th sura (chapter) of the Qur'an.
- (by extension of Moon) Any natural satellite of a planet.
- A month, particularly a lunar month.
- A crescent-like outwork in a fortification.
- The eighteenth trump/major arcana card of the Tarot.
- The thirty-second Lenormand card.
- In hearts, the action of taking all the point cards in one hand.
- To display one's buttocks to, typically as a jest, insult, or protest.
- (usually followed by over or after) To fuss over something adoringly; to be infatuated with someone.
- To spend time idly, absent-mindedly.
- To expose to the rays of the Moon.
- To adorn with moons or crescents.
- (cryptocurrency) Of a coin or token: to rise in price rapidly.
- To shoot the moon.