타산지석이 · 타산지석을
a lesson learned from others' mistakes
Example
다른 회사의 실패를 타산지석으로 삼아야 합니다.
We should learn a lesson from other companies' failures.
Word parts
타 other+산 mountain+지 of+석 stone
Literally 'a stone from another mountain' — even rough stones can polish your jade.
Related words