The most common and most likely answer to this crossword clue is the 6 letter word DIADEM
I've seen this crossword clue in Financial Times
D
I
A
D
E
M
More clues leading to the result DIADEM
- Crown in sea, charity dredged up
- Temple ornament I’d made badly
- Crown princess gets bust made
- Crown found in sea with relief brought back
- Crown
- Former princess made to abandon crown
- Band full of gems — girl briefly had them in EastEnders
- Medieval feudal tax set up to establish regal power
- Support raised with protest, having no love for crown
- Crown Democrat after withdrawing help
Buddy explains!

The straight part
We know that "Crown" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case crown = diadem.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 DIADEM mean?
DIADEM noun- An ornamental headband worn as a badge of royalty.
- A crown.
- Regal power; sovereignty; empire—considered as symbolized by the crown.
- An arch rising from the rim of a crown (rarely also of a coronet), and uniting with others over its centre.
- To adorn with a diadem; to crown.