IPA: /ˌænəˈteɪʃən/
KK: /ænəˈteɪʃən/
A note or comment added to a text to explain or give more information about it.
The teacher provided an annotation on the student's essay to help improve their writing.
Annotation → It is formed from "ad-" (meaning to) and "notare" (meaning to mark). The word refers to the act of marking or adding notes to a text.
Think of adding notes ('ad-') to something you want to mark ('notare') — that's what annotation means.