The most common and most likely answer to this crossword clue is the 9 letter word CONTRONYM
I've seen this crossword clue in Financial Times
C
O
N
T
R
O
N
Y
M
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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 CONTRONYM mean?
CONTRONYM noun- A word that has two opposing meanings, such as cleave (“stick together” or “split apart”).