Check register definition including break down of areas in the definition. Analyzing the definition of key term often provides more insight about concepts. Check register can be defined as: Another name for a cash disbursement journal when the journal has a column for check numbers. Many of us think of a check register when we think of a checkbook, the check register allowing us to record cash payments. A manual accounting system will often use a check register as a discernment journal in order to simplify the recording of cash payments, a check register eliminating the need to post each transaction, instead posting the totals of the check register periodically.