Definition: Endangered species
Species classified by an objective process (e.g. national "Red Book") as being in IUCN categories "critically endangered" and "endangered". A species is considered to be a critically endangered when it is facing an extremely high risk of extinction in the wild in the immediate future. It is considered "endangered" when it is not critically endangered but is still facing a very high risk of extinction in the wild in the near future.
Economic Commission for Europe of the United Nations (UNECE)/ Food and Agriculture Organization of the United Nations (FAO), Terms and Definitions, "Temperate and Boreal Forest Resources Assessment 2000", United Nations, July 1997