足あし元もとに付つけ込こむ

expression, godan verb (-mu)

take advantage of someone's weakness

Rare expression meaning to exploit another's vulnerability or weak point, similar to 足元を見る but more directly predatory.

See also: 足下を見る

• 彼かれは相あい手ての足あし元もとに付つけ込こんで、不ふ利りな契けい約やくを結むすばせた。

  He took advantage of the other party's weakness and made them sign an unfavorable contract.