Extra-long time period (3)
I believe the answer is:
eon
(Other definitions for eon that I've seen before include "Geological period" , "In time, long division" , "Long period of time" , "Vast age; eternity" , "Vast period" .)
I believe the answer is:
eon
(Other definitions for eon that I've seen before include "Geological period" , "In time, long division" , "Long period of time" , "Vast age; eternity" , "Vast period" .)