Yes, cot is a Scrabble word!
...and is worth 5 points in Scrabble, and 6 points in Words with Friends
cot
Noun
1. A sheath worn to protect a finger
2. Baby bed with high sides made of slats
3. A small bed that folds up for storage or transport
What Scrabble words can I make with the letters in cot?
2 Letter Words