noun
circle mark; O mark
A circle used to indicate a correct answer, agreement, approval, or selection. Often contrasted with バツ印 (cross mark).
See also: バツ印
正解の欄に丸印を付けてください。
Please put a circle mark in the correct answer column.
先生は私の答案に丸印をくれた。
The teacher gave me a circle mark on my answer sheet.