1
general::
Phrase(s): bone up (on something)
to study something thoroughly; to review the facts about something. • I have to bone up on the state driving laws because I have to take my driving test tomorrow. • I take mine next month, so I’ll have to bone up, too.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Study intensely, as in I'll have to bone up on my Spanish if I'm to pass the language requirement. The verb bone alone was used in this sense from the mid-1800s on, up being added later. [Slang; late 1800s]
American Heritage Idioms