Yes, cays is a Scrabble word!
...and is worth 9 points in Scrabble, and 9 points in Words with Friends
cays
Noun
1. A coral reef off the southern coast of Florida
What Scrabble words can I make with the letters in cays?
3 Letter Words
2 Letter Words
Noun
1. A coral reef off the southern coast of Florida
3 Letter Words
2 Letter Words