cram for an examination

cram for an/the exam

To study for a test shortly before it is to happen. You might have gotten a higher grade if you didn't cram for the exam at the last minute.
See also: cram, exam

cram for an examination

 and cram for a test
Fig. to study very hard for an exam. I have to go cram fora test now. If you would study during the school term, you would not have to cram.
See also: cram, examination