Duty

That which is due; payment.

That which a person is bound by moral obligation to do, or refrain from doing; that which one ought to do; service morally obligatory.

Hence, any assigned service or business; as, the duties of a policeman, or a soldier; to be on duty.

Specifically, obedience or submission due to parents and superiors.

Respect; reverence; regard; act of respect; homage.

The efficiency of an engine, especially a steam pumping engine, as measured by work done by a certain quantity of fuel; usually, the number of pounds of water lifted one foot by one bushel of coal (94 lbs. old standard), or by 1 cwt. (112 lbs., England, or 100 lbs., United States).

Tax, toll, impost, or customs; excise; any sum of money required by government to be paid on the importation, exportation, or consumption of goods.

the social force that binds you to the courses of action demanded by that force; "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

a government tax on imports or exports; "they signed a treaty to lower duties on trade between their countries"