noun
careless mistake; slip; blunder
A mistake made due to inattention or lack of care, often in work, tests, or daily tasks. Common in business and educational contexts.
テストでケアレスミスをして、簡単な問題を間違えた。
I made a careless mistake on the test and got a simple question wrong.
書類のケアレスミスに気づいて、すぐに修正した。
I noticed a careless mistake in the document and corrected it immediately.