kryptonite

IPA(Pronunciation)

Noun

figuratively uncountable

(figuratively) The one weakness of something or someone that is otherwise invulnerable, an Achilles heel.

Japanese Meaning

普段は無敵であるものでも、唯一持つ致命的な弱点。 / 比喩的に、あらゆる面で完璧に見える存在が持つ唯一の脆弱性、すなわちアキレス腱。

Her kindness was her kryptonite in negotiations, and opponents exploited it every time.

交渉では彼女の優しさが致命的な弱点で、相手はいつもそれを利用した。

Sense（1）

(figuratively) The one weakness of something or someone that is otherwise invulnerable, an Achilles heel.

The terrific seven-grain bread here is the kryptonite of restaurant reviewers: two mini-loaves and you are incapacitated.