Stuffed or packed tightly into a space that's too small, or studied intensively at the last minute.
From Old English 'cramian' or Middle Low German origins. Medieval students would 'cram' for exams, and the modern academic usage solidified by the 1900s.
Neuroscience shows that 'cramming' for tests is way less effective than studying over time, yet students keep doing it — it's because cramming feels like you're learning (it's fresh in short-term memory) even though it doesn't stick!
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