Grammatical term. Figure of speech.

Posted by Samantha on June 22, 2005

Does anyone know what the grammatical term is for the following phrases: "She died of boredom" or "he laughed his head off." Clearly the subjects didn't literally do that. I remember learning it in English, but can't remember for the life of me. It's like metaphor, but that isn't it ... please help if you can.