1. die off - Noun
2. die off - Verb
become extinct
Source: WordNetdie-off
When the money dries up, the sites die off. That's the way to go after piracy. Jared Polis
Nature is an incredible cooperative. When things operate outside of that cooperative, they die off. It's a very simple rule that nature operates under. Tom Shadyac
I've accepted the fact that there's a beginning and end to everything. All species are born, evolve, and then die off. We're going through the 6th great extinction and the large mammals are going first and, you know what - we're large mammals! Yvon Chouinard
Dinosaurs died out Source: Internet
As the Pleistocene epoch drew to a close, one of the largest die-outs caused many mega-fauna to die off, including the last hominid species (excluding Homo sapiens). Source: Internet
Dogs so affected will become gradually weaker in the hind legs as nerves die off. Source: Internet