​. [countable, uncountable] something that you feel you have to do because it is your moral or legal responsibility · ​. [uncountable] the work that is your job. Duty of care · Night duty · Active duty · Jury duty

1[countable, uncountable] something that you feel you have to do because it is your moral or legal responsibility It is my duty to report it to the police.

There are 18 meanings listed in OED's entry for the noun duty, three of which are labelled obsolete. See 'Meaning & use' for definitions, usage, and quotation ...

​duty of care (to somebody) a moral or legal obligation to ensure that other people are safe from physical or mental harm.

/ˌduːti ˈfriː/ ​(of goods) that you can bring into a country without paying tax on them. duty-free cigarettes Topics Shoppingc1, Holidaysc1, Moneyc1.

​having to do something because it is your duty. I felt duty-bound to help him. I felt duty-bound to report the incident. Definitions on the go.

(also active service especially in British English) [uncountable] ​taking part in military action as a member of the armed forces. He has been treated in ...

a responsibility to do something because it is legally or morally right to do it: Every lawyer has a strong sense of duty and ... DUTY-FREE · Heavy-duty · DUTY OF CARE · Customs duty

off-duty adjective /ˌɒf ˈdjuːti/ /ˌɔːf ˈduːti/ (especially of police, military and medical staff) not at work.

duty-bound adjective [not before noun] (formal) having to do something because it is your duty I felt duty-bound to help.