A billion years
The crossword clue "A billion years" is answered by EON, a 3-letter entry. Used 178 times across 27 distinct years; most recently in 2026; first recorded in 1998. It appears in 17 publications in the xd corpus. Every figure on this page comes from the pilot data itself.
The answer
EON
3 letters. See every clue for this answer on the EON answer page.
Used 178 times across 27 distinct years; most recently in 2026; first recorded in 1998. It appears in 17 publications in the xd corpus. Frequency and last-seen figures come from the xd crossword corpus only.
Other answers for this clue
The same clue has also been answered these ways in the xd corpus. Answers inside this pilot link to their own answer page.
- AEON (11 uses in xd)
Other clues for EON
Every other clue in this pilot answered by EON, most used first.
- Long, long time - used 302 times, most recently in 2026
- Very long time - used 212 times, most recently in 2026
Related clues
Pilot clues of the same answer length that share a word with this clue, or match its answer pattern when no word is shared. Most used first.
- Before - ERE, used 733 times
- Greek vowel - ETA, used 549 times
- Superlative suffix - EST, used 521 times
- Mess up - ERR, used 508 times
- Work unit - ERG, used 488 times
- Dawn goddess - EOS, used 446 times
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