Related Clues:
- Celebrates a birthday
- Yellows, or mellows
- Ages disguising son behind Egyptian leader
- Immense time spans
- A long, long, long time
- Huge amount of 50-Across
- Yellows or grays, say
- Nose (anag)
- Units on the geologic time scale
- Long, long stretches
- Not just centuries
- Times and Guardian editors selected leaders therefrom
- An awfully long time
- So long!
- A kazillion years, it seems