marginalia

/ˌmɑrdʒɪˈneɪliə/
noun
  1. Notes, comments, or drawings written in the margins of a book or document.
    • She added her own marginalia to the textbook to help her study for the exam.
    • Scholars study the marginalia in medieval manuscripts to understand how people read in the past.
    • The old library book was full of marginalia from previous readers.
What does "marginalia" mean? | whatsthatwordmean | whatsthatwordmean