Proper noun
Permian-Triassic extinction
(evolutionary theory, geology) A volcanic mass extinction at the end of the Permian period 251.9 million years ago.
Synonyms: Great Dying, Permian-Triassic extinction event, Permian-Triassic mass extinction, end-Permian extinction, end-Permian extinction event, end-Permian mass extinction
Coordinate terms: late-Ordovician extinction, Triassic-Jurassic extinction, Cretaceous-Paleogene extinction, Holocene extinction, Anthropogene extinction
Hypernyms: mass extinction, extinction event, extinction-level event