to keep guard over someone or something; to care for someone or something. Could you please watch over my little girl while I go to the store? I will watch over your house while you are away.
to protect and feel responsible for the care of someone or something She had to watch over her four young children.He watched over his vegetable garden, trying to think up ways to keep the deer away from it.
Guard for protection or safekeeping, as in There were only two aides watching over that large group of children. This idiom was first recorded in 1526.