Meaning of WATCH in English
1》 look at attentively.
↘keep under careful or protective observation.
↘( ~ for ) look out for.
2》 exercise care, caution, or restraint about.
↘[usu. in imperative ] ( ~ out ) be careful.
3》 maintain an interest in.
4》 archaic remain awake for the purpose of religious observance.
1》 a small timepiece worn typically on a strap on one's wrist.
2》 an act or instance of ~ing.
↘a period of vigil, typically during the night.
3》 a fixed period of duty on a ship, usually lasting four hours.
↘(also starboard or port ~ ) the officers and crew on duty during one such period.
↘a shift worked by firefighters or police officers.
4》 (also night ~ ) historical a ~man or group of ~men who patrolled and guarded the streets of a town at night.
be on the ~ be on the alert for danger or trouble.
keep ~ stay on the lookout for danger or trouble.
~ one's (or someone's ) back protect oneself (or someone else) against danger from an unexpected quarter.
the ~es of the night literary waking hours during the night.
OE wæcce '~fulness', wæccende 'remaining awake'; related to wake 1 .
Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004