Yes, dab is a Scrabble word!
...and is worth 6 points in Scrabble, and 7 points in Words with Friends
dab
Verb
1. Apply (usually a liquid) to a surface
2. Hit lightly
Noun
1. A light touch or stroke
2. A small quantity of something moist or liquid
What Scrabble words can I make with the letters in dab?
3 Letter Words
2 Letter Words