A person who stays sober during a social gathering and is responsible for safely driving others from one location to another. Since Kara never drinks alcohol, she always offers to be the designated driver for her friends.

To label or name someone or something as something; to assign someone or something a specific role or status. The boss designated me as the point person for this project, so you guys have to listen to me. No, you can't sit here—mom designated this as the kids' table.