The most common and most likely answer to this crossword clue is the 8 letter word WARINESS
I've seen this crossword clue in The Daily Telegraph
W
A
R
I
N
E
S
S
More clues leading to the result WARINESS
- Tablet’s taken out of fatigue, showing caution
- Is answer uncommon caution?
- After no peace I head for caution
- Woman taking part in battles showing caution
- Answer is modified showing discretion
- Circumspection of one head backing conflict
- Caution! 9 is 13!
- Caution after drug withdrawal out of exhaustion
- Conflict over one point causes mistrust
Buddy explains!

The straight part
We know that "discretion" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case discretion = wariness.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 WARINESS mean?
WARINESS noun- Vigilance or the condition of being alert
- Precautionary forethought to avoid harm or risk