The most common and most likely answer to this crossword clue is the 10 letter word PRINCESSES
I've seen this crossword clue in The Daily Telegraph
P
R
I
N
C
E
S
S
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S
Buddy explains!
The straight part
We know that "Members of the royalty" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case members of the royalty = princesses.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 PRINCESSES mean?
PRINCESSES noun- A female member of a royal family other than a queen, especially a daughter or granddaughter.
- A woman or girl who excels in a given field or class.
- A female ruler or monarch; a queen.
- The wife of a prince; the female ruler of a principality.
- A young girl; used as a term of endearment.
- A young girl or woman (or less commonly a man) who is vain, spoiled or selfish; a prima donna.
- A tinted crystal marble used in children's games.
- A type of court card in the Tarot pack, coming between the 10 and the prince (Jack).
- A female lemur.