Related Clues:
- About a billion years
- Unit in astronomy
- Mind-boggling time
- Million-millennia period
- Vast age
- Inordinately long time
- Two eras or more
- Millions of centuries (Var.)
- About 525 trillion minutes, in astronomy
- Lo-o-o-ong time (Var.)
- Uncountable years
- "___ Flux" (2005 Charlize Theron movie)
- Time in earth's history
- Astronomical time span
- Umpteen years