transitive verb
1. : to polish up or improve by eliminating small imperfections
spent their off time in brushing up their act
2. : to refresh one's memory of : renew one's skill in or knowledge of
brush up your Shakespeare
brushed up his piano technique
intransitive verb
: to refresh one's memory : renew one's skill or knowledge — used with on
brushing up on his golf
brushing up on their understanding of the accepted maritime law — F.L.Paxson
brush up on the significant dates before the history exam