Answer: BRUSHUP

AnswerCrossword Clue
BRUSHUPRenew a skill
BRUSHUPRefresh one's memory, as in "... your Shakespeare"
BRUSHUPGo over one's old notes
BRUSHUPReview for a test
BRUSHUPRefresh one's knowledge (with "on").
BRUSHUPRefresh one's memory of.
BRUSHUPTake a refresher course.
BRUSHUPRevive a skill, with "on"
BRUSHUPReview
BRUSHUPReview for finals
brushupa quick review