Yes, aba is a Scrabble word!
...and is worth 5 points in Scrabble, and 6 points in Words with Friends
aba
Noun
1. A loose sleeveless outer garment made from aba cloth; worn by Arabs
2. A fabric woven from goat hair and camel hair
What Scrabble words can I make with the letters in aba?
3 Letter Words
2 Letter Words