Definitions of economy:

• noun:   an act of economizing; reduction in cost

  Example: "It was a small economy to walk to work every day"

• noun:   frugality in the expenditure of money or resources

  Example: "The Scots are famous for their economy"

• noun:   the efficient use of resources

  Example: "Economy of effort"

• noun:   the system of production and distribution and consumption
• name:  A surname (very rare: popularity rank in the U.S.: #40852)