IPA: /ˈbæŋkˌbʊk/
KK: /bæŋkˌbʊk/
A book that a bank gives to a customer to keep track of their deposits and withdrawals.
I checked my bankbook to see how much money I had left.
Bankbook → The word is formed from "bank" (from Old Italian *banca*, meaning a bench or table for money exchange) and "book" (from Old English *bōc*, meaning a written document or record). A bankbook is a written record of transactions related to a bank account.
Think of a 'bank' where money is exchanged and a 'book' that keeps a record — a bankbook is your record of money transactions.