Crossword Genius

Many millennia (4)

Ross

I think it could be either:

Which length description are you looking for?:

4

4*

aeon

'many millennia' is the definition.
(I've seen this in another clue)

This is the entire clue.

(Other definitions for aeon that I've seen before include "Indefinitely long period of time" , "A very long time, an age" , "Eternity" , "An age; period" , "Vast age" .)

I've seen this clue in The New York Times and the LA Times.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.