Translation guide
Describes a fortress, position, or argument that cannot be captured, overcome, or refuted. Japanese uses different expressions for physical fortifications, metaphorical strength, and logical unassailability.
Describing a physical structure or position that cannot be captured or breached.
A four-character compound meaning 'impregnable' in the sense of a fortress that is difficult to attack and impossible to fall. Commonly used for castles or strong defensive positions.
この城は難攻不落で知られている。
This castle is known for being impregnable.
Literally 'iron-wall defense'. Used to describe an extremely strong, impenetrable defense, often in military or sports contexts.
敵の鉄壁の守りを破るのは難しい。
It's difficult to break through the enemy's impregnable defense.
Means 'solid, firm, strong'. Can describe a fortress or defensive structure that is sturdy and hard to breach. More general than 難攻不落.
その要塞は堅固な造りだ。
That fortress is of impregnable construction.
Describing an argument, logic, or position that cannot be refuted or challenged.
Literally 'there is no room for counterargument'. Used when an argument or position is so solid that it cannot be disputed.
彼の主張は反論の余地がない。
His argument is impregnable.
Means 'unshakable, firm'. Often used for beliefs, positions, or evidence that cannot be moved or doubted.
その証拠は揺るぎないものだ。
That evidence is impregnable.
Literally 'iron wall'. Can be used metaphorically for an argument or alibi that is impossible to break through.
Describing a person who seems emotionally or mentally unassailable, or a mindset that cannot be shaken.
Literally 'one's heart doesn't break'. Describes a person with an unbreakable spirit, often used in casual or motivational contexts.
彼はどんな困難にも心が折れない。
He is impregnable against any hardship.
A Buddhist-derived term meaning 'immovable mind'. Refers to a state of mental calm and unshakability, often used in martial arts or Zen contexts.
不動心を養うことが大切だ。
It is important to cultivate an impregnable mind.
The English word 'impregnable' has no single direct equivalent in Japanese. Translating it as 含浸できない (impregnate-able) would be nonsensical. Always choose an expression based on the specific context: physical defense, logical strength, or mental resilience.
彼のアリバイは鉄壁だ。
His alibi is impregnable.