Meaning ofeonin English

Noun

1. an extremely long period; indefinitely
   The universe has existed for an eon, with its exact age still unknown.
2. an extremely long period (informally, a vast time span)
   Geologists divide earth's history into eons, each representing a significant period.
3. geology's longest time unit; hundreds of millions of years
   The eon of the dinosaurs lasted from around 230 to 65 million years ago.
4. a billion years (short scale)
   The formation of the earth's crust took place over an eon, shaping the planet's surface.
5. 1,000,000,000 years
   The geologic time scale is divided into units of an eon, which is one billion years.