1. thrifty management; frugality in the expenditure or consumption of money, materials, etc.
2. an act or means of thrifty saving; a saving: He achieved a small economy by walking to work instead of taking a bus.
3. the management of the resources of a community, country, etc., especially with a view to its productivity.
4. the prosperity or earnings of a place: Further inflation would endanger the national economy seriously.
5. the disposition or regulation of the parts or functions of any organic whole; an organized system or method.
- from dictionary.com