Yes, yaw is a Scrabble word!
...and is worth 9 points in Scrabble, and 8 points in Words with Friends
yaw
Verb
1. Be wide open
2. Deviate erratically from a set course
3. Swerve off course momentarily
Noun
1. An erratic deflection from an intended course
What Scrabble words can I make with the letters in yaw?
3 Letter Words
2 Letter Words