Feed someone lines

If you “feed someone lines,” you are telling that person, usually an actor, what to say. In the show “Regis and Kathie Lee,” they never had writers “feed them lines,” or tell them what to say. The dialogue was never rehearsed. An assistant might feed his boss lines during a company meeting. There’s another usage for “feed someone a line,” which refers to speaking deceptively to someone. In this use, a “line” refers to a prepared response, perhaps something that the listener wants to hear. If a student forgets to do his homework, he might “feed his teacher a line” about a family emergency, even if there wasn’t one.