アクシデンタル

na-adjective

accidental; unintended; by chance

Used as a na-adjective to describe something happening by accident or not planned. Often seen in technical or formal contexts, but can appear in everyday speech.

• その発はっ見けんはまったくアクシデンタルだった。

  The discovery was completely accidental.

• アクシデンタルな出で来き事ごとで予よ定ていが