1. General: (1) Sum of money that remains unpaid until certain conditions are met. (2) Sum of money kept as a reserve to cover certain contingencies. 2. Banking: (1) Portion of a construction loan amount that is not released until a certain stage (such as completion of the foundation) is reached. (2) Portion of a merchant's revenue held by a credit card processor to cover possible disputed charges, chargeback fees, and other such expenses. 3. Contracting: Portion of payment to a contractor held by a customer until the job is finished to the customer's satisfaction.