Other forms: notebooks
A notebook is the book of empty pages you write your notes in. A ruled notebook, fill a notebook, keep a notebook.
Writing by hand is slower than typing and that is why it works for notes — you cannot take everything down, so you have to decide what matters. Darwin, da Vinci and Woolf all kept them. A notebook is also a small laptop, in older usage.
1nounnotebookA book of blank pages for writing notes.
“The journalist wrote down every word in her notebook.”
notebook is a book.
Also accepted in games: exercise book
From note + book.
Etymology from Wiktionary, CC BY-SA