Meaning of “cram” - Learner’s Dictionary

cram

verb uk us /kræm/ (present participle cramming, past tense and past participle crammed)
cram sth between/in/into, etc

to force things into a small space:

The refugees were crammed into the truck.

[ I ] to study a lot before an exam

(Definition of “cram” from the Cambridge Learner’s Dictionary © Cambridge University Press)