obligation

/ˌɑbləˈgeɪʃən/

the social force that binds you to the courses of action demanded by that force; ; - John D.Rockefeller Jr

中文释义：义务；责任

Parents have a legal obligation to provide for their children.

父母有法律义务抚养子女。

He felt a moral obligation to help the homeless.

他感到有道德义务帮助无家可归者。