Related Clues:
- Geological period (Var.)
- Very long interval
- Long while
- Charlize Theron film, '-- Flux'
- Extremely long stretch
- Almost an eternity (Var.)
- Indefinitely long period
- Geologic span
- A billion years, in geology
- "___ Flux"
- A very, very long time (Var.)
- A billion years, to geologists
- Many generations
- Immeasurably long period of time (Var.)
- Umpteen millennia