Translation

断言する / 主張する / 明言する

Meaning

Aver means to state firmly that something is true, especially in formal, legal, or argumentative writing. It focuses on assertion, not emotion. Do not confuse it with avow, which means openly declare a belief or feeling.

Examples

• 弁護士は、その契約が有効だと断言した。
  The lawyer averred that the contract was valid.
• 著者はその証拠が決定的だと主張している。
  The author avers that the evidence is decisive.