obligation
n. C / Un. something that you must do because it is your duty or because of a law or promise. It is a feeling or a rule that forces you to act in a certain way.
n. a course of action that someone is required to take, whether by legal requirement, social duty, or moral promise. Often implies a binding constraint on one's freedom of choice.
You have a legal obligation to pay your taxes.
The contract creates a clear financial obligation for the tenant to pay the rent on the first of every month.
While the legal obligation was satisfied by the settlement, the CEO felt a moral obligation to issue a public apology to the affected families.
From Middle English obligacioun, from Old French obligacion, from Latin obligatio, obligationem, from obligatum (past participle of obligare), from ob- (“to”) + ligare (“to bind”), from Proto-Indo-European *leyǵ- (“to bind”).
Often used with the verbs 'meet', 'fulfill', or 'honour'. When followed by another action, it typically takes the 'to' + infinitive structure.
I have the obligation of payI have an obligation to payThe noun is typically followed by a 'to' infinitive rather than 'of' + gerund when describing the required action.