UniverseAll of space and everything in it
Definitions:
All existing matter and space considered as a whole; the cosmos
ExtraterrestrialOutside of the earth
Definitions:
Of or from outside the earth or its atmosphere
MultiverseA hypothetical group of multiple universes
Definitions:
A hypothetical collection of potentially diverse observable universes, each of which would comprise everything that is experimentally accessible from a connected region
CosmologyThe study of the universe
Definitions:
The science of the origin and development of the universe
Black holeA region of space having a gravitational field so intense that no matter or radiation can escape
Definitions:
A region of space in which the gravitational field is so powerful that nothing, not even light, can escape its pull after having fallen past its event horizon