The most common and most likely answer to this crossword clue is the 6 plus 2 letter word STEADY ON
I've seen this crossword clue in The Times
S
T
E
A
D
Y
O
N
More clues leading to the result STEADY ON
- Boy grabbing bear by the ears? Watch it!
- That’s too much to say: end broadcast
- Be reasonable, when regular partner is working
- Still being shown? Watch it!
- Exclamation noted, say, when misbehaving
- Keep calm in stable, working
- Place that makes you keep calm
- Calm down relative consuming drink both ends of day
Buddy explains!
The straight part
We know that "Watch it!" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case watch it! = steady on.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.