epoch
//ˈiː.pɒk//
Noun
epochSingular
epochsPlural
1
A period of time in history or a person's life, typically one marked by notable events or particular characteristics.
The invention of the internet marked the beginning of a new epoch in human communication.
2
The beginning of a distinctive period in the history of someone or something.
The invention of the internet marked an epoch in human communication.
3
(Geology) A division of time that is a subdivision of a period and is itself subdivided into ages.
The Holocene epoch began approximately 11,700 years ago.
4
(Astronomy) An arbitrarily fixed date relative to which planetary or stellar measurements are expressed.
The star catalog uses J2000.0 as its standard epoch for celestial coordinates.