Word
eon
US/ˈiɑn/
UK/ˈiːɒn/
UK spelling · aeon
Countable noun
Definition
n. a very, very long period of time. It is often used to describe the age of the universe or the history of the Earth.
n. an extremely long period of time, typically used in geological or astronomical contexts to describe vast chronological spans.
Examples
“It felt like an eon since I last saw my friends.”
“The geologist explained that the formation of the mountain range took place over several eons of tectonic pressure.”
“While human history is measured in millennia, the universe itself has existed for billions of years, spanning an eon of cosmic expansion and stellar evolution.”
Examples
simple
“It felt like an eon since I last saw my friends.”
contextual
“The geologist explained that the formation of the mountain range took place over several eons of tectonic pressure.”
complex
“While human history is measured in millennia, the universe itself has existed for billions of years, spanning an eon of cosmic expansion and stellar evolution.”
Etymology
From Latin aeon, from Ancient Greek αἰών (aiṓn, “age, era”).
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Domains
- Exam level
- CambridgeCambridgeCambridge English QualificationsThe exam suite from Cambridge University Press & Assessment, from A1 Movers up to C2 Proficiency. The benchmark names double as CEFR labels.C1 AdvancedIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.7.0–8.0TOEFL iBTTOEFL iBTTest of English as a Foreign Language, Internet-Based TestETS's academic English test, the standard route for US university admissions. Scored 0–120, with a 1–6 scale since 2026.1–6 scale: 5.0–5.595–113TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.945–990
- Frequency
- Occasional
- Level
- C1 · Advanced
- Updated
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QR code
englishreference.com/q/eon