# mass extinction event

> English word · Noun

## Definitions
1. One of five historical events in which the Earth experienced a loss of ∼75% of all species over a geological interval of less than 3 million years, the most recent being the Cretaceous–Paleogene extinction event 66 million years ago.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/mass-extinction-event