“Penultimate Greek letter” crossword clue

Reveal the answer to see why it works and where this clue has appeared before.PSI is the answer to the New York Times crossword clue “Penultimate Greek letter”. It was last seen in the puzzle of May 14, 2026, where it runs at 10 Across and fills 3 squares. It crosses 3 other entries in that grid — those are listed below and are the quickest way to confirm the letters you already have. This exact clue has run 2 times in NYT puzzles, first on May 14, 2026.