Is this phrase an idiom?

[phorntita]

I wonder whether these words "bone up on"is an idiom cos' I found these sentences on CNN. For the thousand of pages of backgrounders, Hillary Rodham Clinton boned up on for her confirmation hearing a month ago. If "boned up on" is an idiom it'll mean that she studied hard to recall and remind all of her knowledge about things happened in the past which she intended to refresh it. Answer me please?

[Quadratin]

bone up phrasal verb (INFORMAL)
= to learn as much as you can about something for a special reason:
She boned up on economics before applying for the job.

[RonBee]

You can't remind your knowledge, but you can jog (or refresh) your memory.

[Charlie Bernstein]

Originally Posted by phorntita

I wonder whether the words "bone up on" are an idiom, because I found these sentences on CNN.

For the thousands of pages of backgrounders, Hillary Rodham Clinton boned up on for her confirmation hearing a month ago. [That wasn't a sentence.]

If "boned up on" is an idiom, it'll mean that she studied hard to recall and remind herself of all of her knowledge about things that happened in the past which she intended to refresh xxx. Answer me, please.

Yes, it's an idiom, and you've defined it perfectly.

[RonBee]

Bone up on - English Phrasal Verb - UsingEnglish.com

[phorntita]

Thanks a lot Quadratin, Ronbee, Charlie for answering to my question. This is my early thread I made and can't continue to find the way how to get my answer. Now I found it again by searching through the user name Phorntita so now I've got all the names of all the thread I made last time.