What's "cram for" mean?

Native speaker’s answer
Rebecca
To "cram" means to study extremely hard over a short period of time for a test. It's often used to describe last-minute studying, when you are trying to study as much as possible in a very short amount of time. Ex: I have a habit of cramming for tests, so it is very stressful. Ex: She crammed all night for her exam the next morning.