The most common and most likely answer to this crossword clue is the 9 letter word WHITENESS
I've seen this crossword clue in The Daily Telegraph
W
H
I
T
E
N
E
S
S
Buddy explains!

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 WHITENESS mean?
WHITENESS noun- The state of being white (all senses).
- (dysphemistic) The collective of White/Europid people and their historical heritage.