Flyleaf (noun)

1. A blank page at the front or back of a book that is not part of the main text.
2. A blank page used for writing notes or making annotations in a book.

Origin:

From the old english word 'fligelāf' meaning 'leaf of a book'.

Examples:

1. She used the flyleaf of the novel to jot down her thoughts and observations about the story.
2. The first flyleaf of the book was dedicated to the memory of the author's mother.
3. The back flyleaf of the dictionary was filled with handwritten definitions and examples.
4. The collector was pleased to find a signed note from the author on the front flyleaf of the first edition.
5. She used the flyleaves of her textbooks to keep track of important dates, assignments, and grades.