Eras (4)
(Other definitions for eons that I've seen before include "Divisions of archaeological time" , "Endless periods" , "Years and years" , "Divisions of geological time" , "Nose (anag)" .)
'eras' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ages that I've seen before include "(What seems) a very long time" , "A long time (colloq.)" , "Donkey's years" , "Historic periods or prolonged time" , "Aeons" .)
'eras' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for epochs that I've seen before include "Eras, subdivisions of time" , "Distinctive periods in history" , "Divisions of a geological period" , "Divisions of geological periods" , "Vast periods of time" .)