Crossword Genius

Stretch of time

Ross

I think it could be either:

eon

era

(Other definitions for eon that I've seen before include "An immense time" , "Vast age; eternity" , "In time, long division" , "Vast age (alt. sp.)" , "Huge time period" .)

I've seen this clue in The New York 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.