written explanation; letter of explanation; statement of defense
A formal document explaining one's actions or position, often used in legal, business, or official contexts to clarify or justify conduct.
The company submitted a written explanation regarding the suspicion of misconduct.
The statement of explanation detailed why that decision was made.
Compound of 弁明 (explanation, justification) + 書 (document, writing). The exact historical derivation is uncertain, but the word follows a common pattern for formal written statements.