duty

(noun) the social force that binds you to the courses of action demanded by that force. Synonyms: responsibility, obligation. Examples: "We must instill a sense of duty in our children." "Every right implies a responsibility; every opportunity, an obligation; every possession, a duty"- john d.rockefeller jr."

(noun) work that you are obliged to perform for moral or legal reasons. Example: "The duties of the job."

(noun) a government tax on imports or exports. Synonyms: tariff. Example: "They signed a treaty to lower duties on trade between their countries."