Key letter
The crossword clue "Key letter" is answered by PHI, a 3-letter entry. Used 70 times across 27 distinct years; most recently in 2024; first recorded in 1980. It appears in 11 publications in the xd corpus. Every figure on this page comes from the collection data itself.
The answer
PHI
3 letters. See every clue for this answer on the PHI answer page.
Used 70 times across 27 distinct years; most recently in 2024; first recorded in 1980. It appears in 11 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 collection link to their own answer page.
Other clues for PHI
Every other clue in this collection answered by PHI, most used first.
- ___ Beta Kappa - used 266 times, most recently in 2026
- Letter after upsilon - used 76 times, most recently in 2026
- Upsilon follower - used 49 times, most recently in 2026
Related clues
Clues in this collection 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.
- Curvy letter - ESS, used 177 times
- Seventh Greek letter - ETA, used 165 times
- Letter after sigma - TAU, used 161 times
- Letter after pi - RHO, used 139 times
- Letter before omega - PSI, used 132 times
- Letter before tee - ESS, used 124 times
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