Event horizon
/əˈvɛnt həˈɹaɪ.zən/ noun
noun ·Rare ·Advanced level
Definitions
Noun
- 1 The gravitational sphere of a black hole within which the escape velocity is greater than the speed of light.
- 2 The furthest distance in the past of the universe from which light signals from an event can reach an observer at later times.
- 3 A point of no return. broadly, figuratively