<p><strong>Noun</strong></p><ul><li>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.</li><li>Synonyms: responsibility</li><li>something that is done or is to be done for such reasons: to fulfill one's obligations.</li><li>a binding promise, contract, sense of duty, etc.</li><li>the act of binding or obliging oneself by a promise, contract, etc.</li><li>Law: an agreement enforceable by law, originally applied to promises under seal.</li><li>a document containing such an agreement.</li><li>a bond containing a penalty, with a condition annexed for payment of money, performance of covenants, etc.</li><li>Synonyms: covenant, contract</li><li>any bond, note, bill, certificate, or the like, as of a government or a corporation, serving as evidence of indebtedness.</li><li>an indebtedness or amount of indebtedness.</li><li>a favor, service, or benefit for which gratitude is due.</li><li>a debt of gratitude: He felt an obligation to his teacher.</li><li>the state of being under a debt, as of gratitude, for a favor, service, or benefit.</li></ul>