annotation
🇺🇸
/ˌænəˈteɪʃn/
🇬🇧
/ˌænəˈteɪʃn/
A brief explanation or comment added to a text or image to explain or give more information.
The teacher asked students to add annotations to the margins of the book.
先生は学生に本の余白に注釈を加えるよう頼んだ。