PO’CKETBOOK. n.s. [pocket and book.] A paper book carried
in the pocket for hasty notes.
Licinius let out the offals of his meat to interest, and
kept a register of such debtors in his pocketbook. Arbuthnot.
Note down the matters of doubt in some pocketbook, and
take the first opportunity to get them resolved. Watts.
Dr. Johnson's Dictionary 