Idiom: to bomb something
Jim: How did you do on the History final exam yesterday?
Chuck: Actually, I think I bombed it! I didn't study at all.
Jim: What were you thinking? That exam is like one quarter of our overall grade.
Sally: Can you help me study for the Geometry exam that we have next week?
Sally: I am having a hard time in this class and I don't want to bomb the exam.
Cathy: No problem. Let's meet at Starbucks tonight and I'll help you with it.
Meaning: "to bomb something" means to totally fail. It is most often used in an educational context, but it can also be used for such things like job interviews and projects.