This is the 2106th most frequent Polish word.
obowiązek
"Obowiązek" means "duty" or "obligation" in English.
In this case, 'obowiązek' applies to a legal or societal expectation incumbent on all individuals.
Płacenie podatków to obowiązek każdego obywatela.
Paying taxes is the duty of every citizen.
The word 'obowiązek' refers to a duty or responsibility assigned to the speaker in a family or moral context.
Mam obowiązek pomóc młodszemu bratu.
I have the duty to help my younger brother.
Here, 'obowiązek' emphasizes the moral or ethical obligation inherent in the action described.