What is Watch?
Watch is (noun) 1. an object like a little clock which you wear on your wrist She looked at her watch impatiently. What time is it? – my watch has stopped. (NOTE: The plural in this meaning is watches) 2. looking at something carefully Visitors should be on the watch for pickpockets. Keep a watch on the potatoes to make sure they don’t burn. (NOTE: no plural) 3. a period when a soldier or sailor is on duty The men on the night watch didn’t see anything unusual. (NOTE: The plural is watches.) (verb) 1. to look at and notice something Did you watch the TV news last night? We went to the sports ground to watch the football match. Everyone was watching the children dancing. 2. to look at something carefully to make sure that nothing happens Watch the saucepan – I don’t want the potatoes to burn. Can you watch the baby while I’m at the hairdresser’s? 3. to be careful about something watch your language make sure you are not rude watch your step be careful not to do anything wrong
source: Easier English, Student Dictionary Upper Intermediate Level