What term is used for species that are in danger of extinction throughout all or a significant portion of their range?

The term "endangered species" is used to refer to species that face a significant risk of extinction throughout all or a considerable part of their range. This designation indicates that the population of the species has declined sharply or is experiencing a decline due to various factors such as habitat loss, environmental changes, or direct human impacts.

Endangered species are often a focus of conservation efforts, as their loss would have severe impacts on biodiversity and ecological balance. The classification reflects an urgent need for protective measures to prevent extinction, which can involve habitat preservation, legal protections, and recovery programs.

Other terms like "threatened species," "protected species," and "vulnerable species" denote different levels of concern or status within the spectrum of conservation, but specifically, "endangered species" denotes those at the highest risk of disappearing entirely from the planet.