cipherbook
nounUK /ˈsaɪfəbʊk/
US /ˈsaɪfərbʊk/
A cipherbook is a book that helps you write and read secret codes.
The detective found a cipherbook hidden in the old desk.
RELATED WORDS
OTHER MEANINGS
2. A notebook used to record encrypted messages or ciphers.
She wrote all her secret notes in a cipherbook.
3. A reference manual listing cipher systems and their keys.
The spy carried a cipherbook to decode messages from headquarters.
4. A book of puzzles or exercises for practicing code-making and code-breaking.
The children solved puzzles from their cipherbook during class.