Eons

Part of speech: noun

Definitions

1. Extremely long spans of time that are often used to describe geological or astronomical durations
2. Periods of time so vast that they suggest an almost incomprehensible length, usually in history or the universe
3. Incredibly lengthy intervals that extend far beyond normal human experience, often in the realms of earth science or cosmology

Etymology: "Eon" comes from Greek "aion," which meant a lifetime, an age, or a long period of time, and it is the same root that gives us "aeon" and, through Latin, "age." The Greek word's core sense was a span of life or a vital force, and its extension to vast stretches of time came gradually as writers used it for ages without end. English borrowed the word in its learned spelling "aeon" with the sense of an immeasurably long period, and the "eon" spelling became common in American English. The modern scientific sense, a major division of geologic time, is a specialised use: geologists speak of the Phanerozoic Eon, the Proterozoic Eon, and so on, with the spelling "eon" standard in those contexts. The everyday plural "eons" usually appears in phrases such as "for eons," where the sense is an exaggerated and approximate measure of duration rather than a precise figure. The meaning has stayed close to the Greek idea of an extended age while narrowing into a technical unit in geology and astronomy.

Synonyms: ages, eras, millennia, centuries, epochs