sub·trac·tion /səbˈtrækʃən/
  減去,減法
  subtraction
  減法
  subtraction
  減法
  Sub·trac·tion n.
  1. The act or operation of subtracting or taking away a part.
  2. Math. The taking of a lesser number or quantity from a greater of the same kind or denomination; an operation for finding the difference between two numbers or quantities.
  3. Law The withdrawing or withholding from a person of some right to which he is entitled by law.
  Note: ☞ Thus the subtraction of conjugal rights is when either the husband or wife withdraws from the other and lives separate without sufficient reason. The subtraction of a legacy is the withholding or detailing of it from the legatee by the executor. In like manner, the withholding of any service, rent, duty, or custom, is a subtraction, for which the law gives a remedy.
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  subtraction
       n 1: an arithmetic operation in which the difference between two
            numbers is calculated; "the subtraction of three from
            four leaves one"; "four minus three equals one" [syn: minus]
       2: the act of subtracting (removing a part from the whole); "he
          complained about the subtraction of money from their
          paychecks" [syn: deduction] [ant: addition]