Sub*trac"tion (?), n. [L. subtractio a drawing back. See Subtract, and cf. Substraction.]
The act or operation of subtracting or taking away a part.
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.
The withdrawing or withholding from a person of some right to which he is entitled by law.
⇒ 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.
© Webster 1913.