something that one is expected or required to do by moral or legal obligation.

the binding or obligatory force of something that is morally or legally right; moral or legal obligation.

an action or task required by a person's position or occupation; function

the duties of a clergyman.

the respectful and obedient conduct due a parent, superior, elder, etc.

an act or expression of respect.

a task or chore that a person is expected to perform

It's your duty to do the dishes.

Military .

an assigned task, occupation, or place of service

He was on radar duty for two years.

the military service required of a citizen by a country

After graduation, he began his duty.

Commerce . a specific or ad valorem tax imposed by law on the import or export of goods.

a payment, service, etc., imposed and enforceable by law or custom.

Chiefly British . tax

income duty.

Machinery .

the amount of work done by an engine per unit amount of fuel consumed.

the measure of effectiveness of any machine.

Agriculture . the amount of water necessary to provide for the crop in a given area.

Baby Talk . bowel movement. ?

do duty

to serve the same function; substitute for

bookcases that do duty as room dividers.

off duty

not at one's post or work; at liberty

They spent their days off duty in hiking and fishing.

on duty

at one's post or work; occupied; engaged

He was suspended from the force for being drunk while on duty.

noun

disregard , irresponsibility , faithlessness , inconstancy , treachery

noun

burden , business , calling , charge , chore , commission , commitment , committal , contract , devoir , dues , engagement , function , hook * , job , load , millstone * , minding the store , mission , must , need , obligation , occupation , office , onus , ought , pains , part , province , role , service , station , string * , taking care of business , task , trouble , trust , undertaking , weight , work , assessment , custom , customs , due , excise , impost , levy , rate , revenue , tariff , toll , accountability , accountableness , allegiance , amenability , answerability , call of duty , conscience , deference , faithfulness , good faith , honesty , integrity , liability , loyalty , obedience , pledge , respect , reverence , imperative , responsibility , assignment , stint , application , employment , use , utilization , deontology , detail , dharma , fealty , honor , incumbency , noblesse oblige , objective , piety , promise , purpose , shift , tax , trick , watch