Answer:

AEONS

Answer	Crossword Clue
AEONS	Blue moons
AEONS	Ages and ages
AEONS	Just about forever

AEONS	They comprise eternities
AEONS	Billion-year spans
AEONS	Forever, it seems
AEONS	Stretches between ice ages
AEONS	Big times
AEONS	Eternities
AEONS	Millennia upon millennia
AEONS	Very long time

AEONS	Many moons
AEONS	Almost eternity
AEONS	Time spent in line, seemingly
AEONS	Many, many centuries
AEONS	Very long times
AEONS	Seemingly forever
AEONS	Ages
AEONS	Geologic time periods

AEONS	Billions of years
AEONS	Forever, or close to it
AEONS	Geologic spans
AEONS	Long time periods
AEONS	Light-years
AEONS	Time periods.
AEONS	Many years.
AEONS	Thousands and thousands of years.

AEONS	Billions of years.
AEONS	Untold years.
AEONS	Eternity.
AEONS	Ages and ages.
AEONS	Eternities.
AEONS	Thousands of years.
AEONS	Geologic times.
AEONS	Long times.

AEONS	Long times
AEONS	Kalpas
AEONS	Time periods
AEONS	Long periods
AEONS	Millennia