The most common and most likely answer to this crossword clue is the 15 letter word STANDARD-BEARER
I've seen this crossword clue in Financial Times
S
T
A
N
D
A
R
D
-
B
E
A
R
E
R
More clues leading to the result STANDARD-BEARER
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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 STANDARD-BEARER mean?
STANDARD-BEARER noun- A person who carries a flag or banner (a standard).
- A person who visibly leads.