Related Clues:
- It seemingly never ends
- "___ Flux" (Charlize Theron film)
- 1,000,000,000 years, in geology
- Vast timeframe
- "___ Flux" (animated series)
- Long historical episode
- Long stretch of time
- About a billion years
- Unit in astronomy
- Mind-boggling time
- Million-millennia period
- Vast age
- Inordinately long time
- Important historical period
- Two eras or more