Yes, dreg is a Scrabble word!
...and is worth 6 points in Scrabble, and 7 points in Words with Friends
dreg
Noun
1. A small amount of residue
What Scrabble words can I make with the letters in dreg?
3 Letter Words
2 Letter Words
Noun
1. A small amount of residue
3 Letter Words
2 Letter Words