The most common and most likely answer to this crossword clue is the 7 letter word SCEPTRE
I've seen this crossword clue in The Times
S
C
E
P
T
R
E
More clues leading to the result SCEPTRE
- Secret repositioning with parking reserved for staff
- Heading for parliament in secret, maltreated royal staff
- Respect is high for royal staff
- Odd characters in secret exercises concerning staff
- Saint Peter prepared to carry the top of Christ’s ceremonial staff
- Month carrying council leader on the staff
- May come to respect a sign of authority
- Staff threat, as numbers two and four are exchanged
- Abnormal respect for symbol of authority
- Power possessed by mysterious secret ceremonial staff
Buddy explains!

The straight part
We know that "royal staff" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case royal staff = sceptre.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 SCEPTRE mean?
SCEPTRE noun- An ornamental staff held by a ruling monarch as a symbol of power.
- To give a sceptre to.
- To invest with royal power.