大おお間ま違ちがい

noun

great mistake; serious error; blunder; complete misunderstanding

Emphasizes a very large or fundamental mistake, often with a nuance of surprise or criticism. Can refer to factual errors, misjudgments, or complete misunderstandings.

• それは大おお間ま違ちがいだ。

  That's a huge mistake.

• 彼かれの説せつ明めいを聞きいて、大おお間ま違ちがいに気きづいた。

  After hearing his explanation, I realized my serious error.

• そんなことを信しんじるなんて大おお間ま違ちがいだ。

  Believing something like that is a complete misunderstanding.