Yes, flaw is a Scrabble word!
...and is worth 10 points in Scrabble, and 11 points in Words with Friends
flaw
Verb
1. Add a flaw or blemish to; make imperfect or defective
Noun
1. An imperfection in an object or machine
2. Defect or weakness in a person's character
3. An imperfection in a plan or theory or legal document that causes it to fail or that reduces its effectiveness
What Scrabble words can I make with the letters in flaw?
3 Letter Words
2 Letter Words