aeon

From Longman Dictionary of Contemporary Englishaeonae‧on, eon /ˈiːən/ noun [countable]    LONG TIMEan extremely long period of timeExamples from the CorpusaeonFor an aeon of time the words meant nothing.And the cast, leaping from aeon to aeon, does a remarkable job.Minute after minute, aeon after aeon, Nothing lets up or develops.For our decade-conscious brains, an event that happens only once per aeon is so rare as to seem a major miracle.The seas powdering our bones like quartz, making sand, grinding our peace for us by the aeon.