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Eon

/ˈiːɒn/noun

An immense stretch of time, and in geology the largest formal division, ranking above the era.

The Greek roots

αἰών
aiṓn
age, lifetime

Literally: a lifetime, an age

Follow a root:αἰών2 words

The story of the word

In Homer αἰών is a person's own span of life, close to a life force: when it leaves the body, the man is dead. Gnostic writers of the second century turned Aeons into emanated divine beings, plural and named. Geologists then made it a measured unit, so the Phanerozoic Eon now means a specific 539 million years rather than a vague forever.

How it travelled
Ancient Greek → Latin → English
First recorded
1640s

In a sentence

Bacteria had the planet to themselves for eons before anything grew a shell.

Built on the same root

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