DUTY(IES) (noun)

1. something that one is expected or required to do by moral or legal obligation.
2. the binding or obligatory force of something that is morally or legally right; moral or legal obligation.
3. an action or task required by a person's position or occupation; function: the duties of a clergyman.
4. the respectful and obedient conduct due a parent, superior, elder, etc.
5. an act or expression of respect.
6. a task or chore that a person is expected to perform: It's your duty to do the dishes.
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—Syn.1. DUTY, OBLIGATION refer to what one feels bound to do. DUTY is what one performs, or avoids doing, in fulfillment of the permanent dictates of conscience, piety, right, or law: duty to one's country; one's duty to tell the truth, to raise children properly. An OBLIGATION is what one is bound to do to fulfill the dictates of usage, custom, or propriety, and to carry out a particular, specific, and often personal promise or agreement: financial obligations. 3. responsibility, business. 4. deference.

* Excerpted from the Random House Webster's Unabridged Dictionary 3.0.