If you tell someone to watch out, you are warning them to be careful, because something unpleasant might happen to them or they might get into difficulties.
You have to watch out because there are land mines all over the place. [VERBPARTICLE]
The casinos in Las Vegas had better watch out since I'm obviously on a lucky streak! [VERBPARTICLE]
See full dictionary entry for watch
watch out in British English
verb
1. (intr, adverb)
to be careful or on one's guard
nounwatchout
2. a less common word for lookout (sense 1)
watch out in American English
US
to be alert and on one's guard; be careful
See full dictionary entry for watch
Examples of 'watch out' in a sentence
watch out
Then you tell her watch out, the boogie man is going to get her.
Reeves, Robert DOUBTING THOMAS
She smiled then, the long, curling smile he had learned to watch out for.
Meek, M R D A WORM OF DOUBT
You just didn't know the potential pitfalls to watch out for.
Isobel Bird CIRCLE OF THREE: BOOK 7: BLUE MOON (2001)
In other languages
watch out
British English: watch out /wɒtʃ aʊt/ VERB
If you tell someone to watch out, you are warning them to be careful, because something unpleasant might happen to them or they might get into difficulties.
You have to watch out – there are dangers everywhere.