Definition of: duty

(d′tē, dy′-) noun plural ·ties
1. That which one is bound, by any natural, legal, or moral obligation, to pay, do, or perform.
2. Specific obligatory service or function, as of a soldier, sailor, etc.: He is on sea duty.
3. The obligation to do that which is prescribed or required, especially by the moral law; moral obligation; right action.
4. An impost or customs tax, as upon goods imported, exported, or consumed.
5. Agric. a The quantity of water necessary, in artificial irrigation, to supply adequately a definite surface of land. b The acreage which a stated amount of water will adequately serve: called duty of water.
6. Mech. a The efficiency of or useful work done by an engine or motor under stated conditions. b The efficiency of a steam engine expressed in terms of its capacity to lift a definite weight one foot high while consuming a certain quantity of coal.
7. A formal expression of respect.
—customs duty A tax levied on imports (or exports) for purposes of revenue or, more commonly, for the protection of domestic manufacturers. [<AF duete <du DUE] Synonyms: accountability, business, function, obligation, office, responsibility, right, righteousness. Etymologically, duty is that which is owed or due; obligation, that to or by which one is bound; right, that which is correct, straight, or in the direct line of truth and goodness; responsibility, that for which one must answer. Duty and responsibility are thought of as to some person or persons; right is impersonal. One's duty may be to others or to himself; his obligations and responsibilities are to others. Duty arises from the nature of things; obligation and responsibility may be created by circumstances, as by one's own promise, or by the acceptance of a trust, etc. We speak of a parent's duty, a debtor's obligation; or of a child's duty of obedience, and a parent's responsibility for the child's welfare. Right is that which accords with the moral system of the universe. Righteousness is right incarnated in action. In a more limited sense, right may be used of what one may rightly claim, and so be the converse of duty. It is the creditor's right to demand payment, and the debtor's duty to pay. Compare BUSINESS, TAX, VIRTUE.