Meaning of “watch” - Learner’s Dictionary

watch

noun uk us /wɒtʃ/
CLOCK [ C ]

A1 a small clock on a strap that you fasten round your wrist (= lower arm):

I don't wear a watch.
ATTENTION [ U, no plural ]

If you keep a watch on something or someone, you watch or give attention to them, especially to make sure nothing bad happens:

We're keeping a close watch on the situation.

(Definition of “watch noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)