it also means ::force something or somebody into a small space, as if you were in a concert and it is crowded and you are among people and there´s not much space between each other, then you are crammed up. i hope i made myself understood.

To "cram" for a test is to study extremely hard and long just before a test, "cramming" the information into your head. It usually happens the day (and night) before a big test. Usually students get very little sleep while they are cramming. It may be that they didn't study enough earlier and are trying to make up for it. Or possibly they did study hard before and are trying to make sure they get a good grade.

It means to study very hard just before the exam eg if your exam is at 9am on Monday, you might cram[ study] till late at night on Sunday. If you need more time to cram, it means that you haven't studied enough and are doing it at the last minute.

Hi... It is to study or work very hard, usually before a test or an exam...