Mug up
Definition 1 of 1
Pro Tip 1/3Last Minute Prep
Often implies hurried or last-minute studying, usually right before an event like an exam. 
I need to mug up on Shakespeare tonight; my literature test is tomorrow!
Pro Tip 2/3Informal Context
'Mug up' is informal and more common in British English, not typically used in formal writing. 
During lunch, Sarah told her friend she's going to mug up for her interview.
Pro Tip 3/3Temporary Learning
Suggests memorization for short-term retention rather than deep understanding or long-term knowledge. 
He had to mug up the procedures quickly to pass the practical test.