Royal persons (5)
I believe the answer is:
regal
'royal' is the definition.
(synonyms)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for regal that I've seen before include "Kingly or queenly" , "King-like" , "Kingly glare?" , "Fit for a king" , "Portable organ" .)