The most common and most likely answer to this crossword clue is the 6 letter word BEWARE
I've seen this crossword clue in The Sunday Telegraph
B
E
W
A
R
E
More clues leading to the result BEWARE
- Steer clear of social worker introducing great conflict
- Conflict divides work team in cave
- Caution: six-footer is full of hostility
- Who’s busy covering conflict in cave?
- Guard against black sheep eating a rook
- Look out for period with internet being up
- We’ll turn up in empty cave
- Warning from worker about fight
- Worker about to fight – watch out!
- Bear, we suspect, in cave
Buddy explains!
The straight part
We know that "Watch ou" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case watch ou = beware.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 BEWARE mean?
BEWARE verb- (defective) To use caution, pay attention to (used both with and without of).