Wiktionary
n. (context finance economics English) Direct investment into production or business in a country by an individual or company of another country, either by buying a company in the target country or by expanding operations of an existing business in that country.
WordNet
n. investing in United States businesses by foreign citizens (often involves stock ownership of the business)
a joint venture between a foreign company and a United States company
Wikipedia
A foreign direct investment is an investment in the form of a controlling ownership in a business enterprise in one country by an entity based in another country. It is thus distinguished from foreign portfolio investment by a notion of direct control.
The origin of the investment does not impact the definition as an FDI: the investment may be made either "inorganically" by buying a company in the target country or "organically" by expanding operations of an existing business in that country.
Usage examples of "foreign direct investment".
If they accept foreign direct investment, they will have the opportunity to begin dealing with their technology problems fairly quickly.