弱み

weakness, weak point

weak + forms nouns denoting a quality, state, or experience (“-ness”)
noun Rare #41,005
weakness, weak point
JA: 彼の弱みを知っている。
EN: I know his weakness.

彼の弱みに付け込むのはやめなさい

Stop taking advantage of his weakness.

弱みがあった

I had a weakness.

— ア・フュー・グッドメン (1992)

人の弱みに付け込むことはやめろよ

Stop taking advantage of people's weaknesses.

ジョンビル弱みに付け込んだ

John took advantage of Bill's weakness.