Related Clues:
- Time to evolve?
- How long it takes mountains to form
- Basically forever
- Many, many centuries
- Ages disguising son behind Egyptian leader
- Immense time spans
- A long, long, long time
- Huge amount of 50-Across
- Crumbling as one ages
- Nose (anag)
- Units on the geologic time scale
- Long, long stretches
- Not just centuries
- So long!
- A kazillion years, it seems