eon
Geological time unit
An eon is an immensely long period of time.
In geology, it's the largest division of Earth's history, spanning hundreds of millions of years.
In everyday use, eon is hyperbolic: I haven't seen you in eons.
The word suggests time so vast it becomes almost abstract.
Also spelled aeon, especially in British English.
Study of rock layers
- PrecambrianEarliest geological eon
- PaleozoicEarly complex-life epoch
- MesozoicAge of Reptiles
- CenozoicPresent geological era
Archean · Proterozoic · geochronology · strata · fossils · supercontinent · Pangaea · Gondwana
Extended time spans
- epochDistinct historical period
- eraDistinct historical period
- periodPunctuation ending sentences
- spanDistance between endpoints
stretch · lifetime · millennia · centuries · generations · long-time · years · awhile
Unlimited extent or quantity
- perpetuityInfinite continuation of time
- everlastingLasting for all time
- timelessnessFreedom from temporal decay
- endlessWithout termination or boundary
unending · eternal · ageless · forever · immemorial · forevermore · ages · eternally
Complete system or domain
- galaxyGravitationally bound stellar mass
- cosmologyStudy of universal structure
- space-timeFused dimensional framework
- stellarOf or like celestial bodies
lightyear · deep-space · galactic · astronomical · cosmos · celestial · nebula · astrophysics
stratigraphy
Study of rock layers
- PrecambrianEarliest geological eon
- PaleozoicEarly complex-life epoch
- MesozoicAge of Reptiles
Cenozoic · Archean · Proterozoic · geochronology · strata · fossils · supercontinent · Pangaea · Gondwana · radiometric
ages
Extended time spans
span · stretch · lifetime · millennia · centuries · generations · long-time · years · awhile · interval
infinity
Unlimited extent or quantity
- perpetuityInfinite continuation of time
- everlastingLasting for all time
- timelessnessFreedom from temporal decay
endless · unending · eternal · ageless · forever · immemorial · forevermore · ages · eternally · sempiternal
universe
Complete system or domain
- galaxyGravitationally bound stellar mass
- cosmologyStudy of universal structure
- space-timeFused dimensional framework
stellar · lightyear · deep-space · galactic · astronomical · cosmos · celestial · nebula · astrophysics · spacetime