The most common and most likely answer to this crossword clue is the 9 letter word OBSCURITY
I've seen this crossword clue in The Times
O
B
S
C
U
R
I
T
Y
More clues leading to the result OBSCURITY
Buddy explains!
The straight part
We know that "in darkness" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case in darkness = obscurity.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 OBSCURITY mean?
OBSCURITY noun- Darkness; the absence of light.
- The state of being unknown; a thing that is unknown.
- The quality of being difficult to understand; a thing that is difficult to understand.