noun, noun or participle which takes 'suru', transitive verb
annotation; explanatory notes; commentary
Refers to notes or commentary added to a text to explain difficult points. Can be used as a noun or as a suru-verb meaning 'to annotate'.
古典の注解を読むと理解が深まる。
Reading annotations on classical texts deepens your understanding.
先生は難しい単語に注解を付けてくれた。
The teacher added explanatory notes to the difficult words.