The most common and most likely answer to this crossword clue is the 9 letter word SUPERSTAR
I've seen this crossword clue in The Daily Telegraph
S
U
P
E
R
S
T
A
R
More clues leading to the result SUPERSTAR
- Big celeb displays wonderful heavenly body
- Celebrity right to enter pastures new
- Senior policeman grasses up George Clooney, for one
- Rising Democrat’s rep used to bring in A-list celeb
- A-lister informs Republican American to retire
- On a list up in South Queens: volunteers required
- Part’s sure to be rewritten for celebrity
- Top actor on excellent path leading to highest rank
- Hero drinks tea without hesitation
Buddy explains!

The straight part
We know that "celebrity" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case celebrity = superstar.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 SUPERSTAR mean?
SUPERSTAR noun- Someone who has accumulated a vast amount of fame; a high-level celebrity.