noun
Eternity, the duration of the universe.
An immeasurably or indefinitely long period of time.
(US, informal, hyperbolic) A long period of time.
(astronomy, geology) A period of one billion (short scale, i.e. 1,000,000,000) years.
(geology) The longest geochronologic unit, being a period of hundreds of millions of years; subdivided into eras.
(Gnosticism, usually spelled aeon or æon) A spirit being emanating from the Godhead.