Translation

絶対に誤らない / 間違いのない / 失敗しない

Meaning

Infallible means unable to be wrong, mistaken, or unsuccessful. It is often used in negative sentences because few real methods or people are truly infallible. The trap is overusing it when reliable or useful would be more accurate.

Examples

• どんな医療検査も絶対に誤らないわけではありません。
  No medical test is infallible.
• 彼女は自分の記憶が絶対ではないことを認めました。
  She admitted that her memory was not infallible.