Geological periods (4)
'geological periods' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for eons that I've seen before include "Divisions of archaeological time" , "Years and years" , "Nose (anag)" , "Divisions of geological time" , "Very long periods (US)" .)
'geological periods' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for eras that I've seen before include "typeface" , "At least two times" , "Epochs" , "Periods of time" , "Periods, ages" .)