Hidden inside psi sit pis, psi, and sip, three-letter plays tied at the top of this rack with 5 points in Scrabble apiece. In all, 6 valid words come out of this rack, grouped by length below and checked for Words With Friends as well as Scrabble.
pis, psi, and sip tie for the highest Scrabble score from psi at 5 points. The top 6 of 6 words are shown here, with the full list organized by length below.
There are 3 three-letter words hiding in psi: two come from rearranging its letters, and psi itself is already a playable word with no unscrambling required. If a familiar word is all you need, start with sip. For points, the strongest plays are pis, psi, and sip — each worth 5 points in Scrabble.
37 four-letter words can be made using all the letters in psi plus one additional letter.
Swap a single tile in psi and you get a different three-letter rack with its own word list. None of these appear in the results above — they share 2 of the 3 letters, not all of them.
psi is in the NWL, the official Scrabble word list for North America, and in the Words With Friends dictionary, so it's playable exactly as it stands and needs no unscrambling.
The 1-point gap between the two totals comes from the tile values themselves: Scrabble and Words With Friends price the same letters differently.
Dictionaries record two senses for psi. Scrabble and Words With Friends score tiles and not meanings, so every sense below is worth the same 5 points on a Scrabble board:
psi is one of three three-letter words the same letters produce. No arrangement of the same tiles scores higher in Scrabble, so playing psi unchanged also takes the maximum points these letters offer.
The highest-scoring plays from these letters are pis, psi, and sip, worth 5 points in Scrabble, and nothing else built from psi earns more points in Scrabble. Words With Friends prices the same letters differently, so the top of the list changes on a Words With Friends board. Both scores count tile values only and exclude premium squares.
The letters in psi produce 6 valid words in the Scrabble and Words With Friends dictionaries. The word count by length is: 3 three-letter words and 3 two-letter words.