existential risk

Etymology
The "human extinction" sense was.

Noun

 * 1) A risk which could destroy or permanently damage an entity; a risk to one's existence.
 * 2)  A hypothetical future event which could cause human extinction or permanently and severely curtail humanity's potential.
 * 1)  A hypothetical future event which could cause human extinction or permanently and severely curtail humanity's potential.
 * 1)  A hypothetical future event which could cause human extinction or permanently and severely curtail humanity's potential.