| Answer | Crossword Clue |
|---|---|
| EON | A billion years, in geology |
| EON | One billion years, in geology |
| EON | A billion years, in astronomy |
| AEON | A billion years, in astronomy (Var.) |
| universes | All existing matter and space considered as a whole; the cosmos. The universe is believed to be at least 10 billion light years in diameter and contains a vast number of galaxies; it has been expanding since its creation in the Big Bang about 13 billion years ago |
| EONS | Billion-year increments, in geology |
| EON | 1,000,000,000 years, in geology |
| EON | One billion years, in astronomy |
| EON | One billion years in ONE? |
| EON | One billion years, in geologic time |
