noun
eon
EE-on
Eon (noun) means an extremely long or indefinite period of time. Example: “It felt like eons since we last spoke.”
noun
1
An extremely long or indefinite period of time.
"It felt like eons since we last spoke."
"Eons of erosion carved out the canyon."
"Waiting for the results felt like an eon."
2
technical In geology, the largest division of geological time, made up of several eras.
"The Phanerozoic eon covers the time since complex life became abundant."
"Geologists divide Earth's history into a handful of eons."
"Each eon is broken down into smaller eras and periods."
How to use eon
Learner’s notesIn plain EnglishAn eon is a huge stretch of time, whether used loosely or as a precise unit in geology.
When to use it
The everyday sense is casual and exaggerated, while the geological sense is precise and technical.
Memory tip
In British English you'll often see the spelling 'aeon' instead of 'eon'.
Trace the full origin ↓
Common pairings
eons ago
for eons
geological eon
eons of time
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Etymology
The word comes from Latin 'aeon', which itself derives from the Ancient Greek 'aion', meaning age or era.
Synonyms
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age
aeon
Antonyms
Related words
Rhymes for eon
See all rhymes for eon →Frequently asked questions
What does 'eon' mean?
It means an extremely long or indefinite stretch of time, and in geology it refers to the largest formal division of Earth's history.
Is 'eon' the same as 'aeon'?
Yes, 'aeon' is simply an alternative spelling of 'eon', more commonly used in Commonwealth English.
How long is a geological eon?
A geological eon spans hundreds of millions of years and is made up of several smaller eras.
What is the meaning of eon?
"eon" (noun) means an extremely long or indefinite period of time.
