鍥而不捨

Simplified: 锲而不舍

qiè'érbùshě ㄑㄧㄝˋ ㄦˊ ㄅㄨˋ ㄕㄜˇ

    • to chip away at a task and not abandon it (idiom) to chisel away at sth
    • to persevere
    • unflagging efforts

Character by character

Sources