\Du"ty\, n.; pl. {Duties}. [From {Due}.]
1. That which is due; payment. [Obs. as signifying a material
   thing.]
         When thou receivest money for thy labor or ware,
         thou receivest thy duty.              --Tyndale.
2. That which a person is bound by moral obligation to do, or
   refrain from doing; that which one ought to do; service
   morally obligatory.
         Forgetting his duty toward God, his sovereign lord,
         and his country.                      --Hallam.
3. Hence, any assigned service or business; as, the duties of
   a policeman, or a soldier; to be on duty.
         With records sweet of duties done.    --Keble.
         To employ him on the hardest and most imperative
         duty.                                 --Hallam.
         Duty is a graver term than obligation. A duty hardly
         exists to do trivial things; but there may be an
         obligation to do them.                --C. J. Smith.
4. Specifically, obedience or submission due to parents and
   superiors. --Shak.
5. Respect; reverence; regard; act of respect; homage. ``My
   duty to you.'' --Shak.
6. (Engin.) 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).
7. (Com.) Tax, toll, impost, or customs; excise; any sum of
   money required by government to be paid on the
   importation, exportation, or consumption of goods.
Note: An impost on land or other real estate, and on the
      stock of farmers, is not called a duty, but a direct
      tax. [U.S.]
{Ad valorem duty}, a duty which is graded according to the
   cost, or market value, of the article taxed. See {Ad
   valorem}.
{Specific duty}, a duty of a specific sum assessed on an
   article without reference to its value or market.
{On duty}, actually engaged in the performance of one's
   assigned task.