AEON

The word aeon, also spelled eon, originally meant "life", "vital force" or "being", "generation" or "a period of time", though it tended to be translated as "age" in the sense of "ages", "forever", "timeless" or "for eternity". In Greek, it literally refers to the timespan of one hundred years. A cognate Latin word aevum for "age" is present in words such as eternal, longevity and mediaeval. (Wikipedia)