As a verb: asking someone a question with the idea that their answer will serve as the necessary conversational opening for you to tell some big story about yourself.
Dwayne: Have you ever been to France?
Shawna: Yes, I went there for two weeks with my family last summer.
Dwayne: I spent three months in France last summer, and man, I really know a lot about French life now. Let me tell you about this cafe I went to in Nice ... Bla bla.
Shawna: Ooh la la, does he know how to springboard!
Your teacher has assigned several homework assignments whose due-dates are spaced out over the course of the semester. You don't bother to do any of them. The night before the final, you realize what a mistake that was, and you hurriedly do all of the homework assignments in succession. On entering the final exam, you plop the lot of them on the teacher's desk, unceremoniously and without explanation. This hail-Mary hand-in subsequently becomes an object of incredulity and amusement among your teacher's colleagues.
Can you believe that Dwayne D. pulled a hail-Mary hand-in on me at the final? He must be delusional.