something by which a person is bound or obliged to do certain things, and which arises out of a sense of duty or results from custom, law, etc.
something that is done or is to be done for such reasons: to fulfill one's obligations.
a binding promise, contract, sense of duty, etc.
the act of binding or obliging oneself by a promise, contract, etc.
Law. an agreement enforceable by law, originally applied to promises under seal. a document containing such an agreement. a bond containing a penalty, with a condition annexed for payment of money, performance of covenants, etc.