the practice of brushing up a skill

to brush up (a skill, knowledge, etc.) / to review or improve (something)

skill (capacity to do something well)

every day; daily

everyday life; daily life

(often in compounds) a brush (implement comprising bristles and a handle)

blusher, blush (makeup to redden cheeks)

Alternative form of 勉強

to study / to discount, to reduce the price of something

studying, studies, study