noun, noun or participle which takes 'suru', transitive verb
polish (gems); cultivate (skills, character)
Literally, polishing gems or jade. Figuratively, refining one's skills, knowledge, or character through diligent effort. Often used in formal or literary contexts.
彼は長年、技術を琢磨してきた。
He has been polishing his skills for many years.
学
Devote oneself to the cultivation of learning.