The harm to a country's wider economy when a boom in one sector (typically natural-resource exports or a large inflow of foreign money) pushes up the exchange rate and makes the country's other tradable industries, especially manufacturing, uncompetitive.
The definition (a resource or inflow boom appreciating the currency and crippling other exports) and the Netherlands origin are testable named-phenomenon facts.
Dutch disease is not a literal illness; it is the economic damage from currency appreciation triggered by a resource or capital boom, weakening other tradable sectors, especially manufacturing.
A resource or inflow boom appreciates the currency and makes other exports (manufacturing) uncompetitive; named after the 1960s Netherlands gas boom.