A stew is a meal which you make by cooking meat and vegetables in liquid at a low temperature.

When you stew meat, vegetables, or fruit, you cook them slowly in liquid in a closed dish.

If you are in a stew, you feel very worried.

If you let a person stew or if you leave them to stew, you deliberately allow them to worry about something for a while, rather than telling them something which would make them feel better.