執しゅう念ねん深ぶかい

i-adjective

tenacious; persistent; stubborn; vindictive; spiteful; vengeful

Describes a person who holds onto a grudge or desire with intense, often negative, persistence. The word combines 執念 (deep-seated obsession/grudge) with 深い (deep), emphasizing an unyielding, sometimes vengeful fixation.

• 彼かれは執しゅう念ねん深ぶかくて、何なん年ねんも前まえのことをまだ根ねに持もっている。

  He is so tenacious that he still holds a grudge about something from years ago.

• あの人ひとは執しゅう念ねん深ぶかいから、一いち度ど敵てきに回まわすと怖こわいよ。

  That person is vindictive, so it's scary to make an enemy of them.