Wiktionary
vb. (context intransitive idiomatic English) To study or cram, especially in order to refresh one's knowledge of a topic.
WordNet
Usage examples of "bone up".
I cried to Dorn and Shattnir in my head, screamed at them to help me raise that bone up, to feed me the power to raise that bone up, screamed to Wafnor to break the soil at its base, to all of them to look, see, join, move, fight.
If somebody absolutely pushed T-Bone up against the wall, when the only option was kill or be killed, he’.
He held the bone up for Trapspringer's inspection and sucked in his breath.
He stirred the fire, standing slender tusks of bone up out of the ashes.
Prescott gave me back the deadpan look, but buried beneath it were traces of the discomfort that I needed to see to stop me reaching across the cab and smashing her nose bone up into her brain with one stiffened hand.