obligation

1. General: Bond of moral duty (whether of necessity or of one's own choosing) that ties two or more parties together.

2. Accounting: Duty to make future payment that is incurred as soon as a purchase order is placed, encumbers a certain sum of money, and is called obligation incurred.

3. Legal: Liability or duty to do something or refrain from doing something under the terms of a contract, such as the obligation of a borrower (the obligor) to pay back the lender (the obligee) under the terms of the loan agreement. Obligations usually involve a penalty for non-fulfillment.