Idioms and Phrases with rub up on
rub up on
Refresh one's knowledge, as in I must rub up on my French before we leave for Paris. [Second half of 1700s] Also see brush up, def. 2.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.