noun (n)

• an arithmetic operation in which the difference between two numbers is calculated(noun.act)

  Example:
  The subtraction of three from four leaves one.
  

  Synonym:
  minus
  

  source: wordnet30
• the act of subtracting (removing a part from the whole)(noun.act)

  Example:
  He complained about the subtraction of money from their paychecks.
  

  Synonym:
  deduction
  Antonym:
  addition
  

  source: wordnet30
• The act or operation of subtracting or taking away a part.(noun)

  source: webster1913