Final answer:
A reduction in the bank account of a merchant by a credit card company is termed chargeback.
Step-by-step explanation:
The reduction in the bank account of a merchant by a credit card company is termed chargeback. When a customer disputes a charge on their credit card statement, the credit card company may initiate a chargeback, which results in the reversal of funds from the merchant's account.
This process is typically used to protect consumers from fraudulent charges or unsatisfactory purchases. The credit card company investigates the disputed transaction and, if found valid, refunds the customer while debiting the merchant's account.