cos and soc tie for the highest Scrabble score from cos at 5 points. The top 4 of 4 words are shown here, with the full list organized by length below.
There are 2 three-letter words hiding in cos: one comes from rearranging its letters, and cos itself is already a playable word with no unscrambling required. No common everyday answer stands out among these three-letter results, so let the score decide: the highest-scoring words are cos and soc, each worth 5 points in Scrabble.
Swap a single tile in cos 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.
cos 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 cos. Scrabble and Words With Friends score tiles and not meanings, so every sense below is worth the same 5 points on a Scrabble board:
cos is one of two three-letter words the same letters produce. No arrangement of the same tiles scores higher in Scrabble, so playing cos unchanged also takes the maximum points these letters offer.
The highest-scoring plays from these letters are cos and soc, worth 5 points in Scrabble, and nothing else built from cos 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 cos produce 4 valid words in the Scrabble and Words With Friends dictionaries. The word count by length is: 2 three-letter words and 2 two-letter words.