Yes, abs is a Scrabble word!

Noun

1. Any of a class of composite plastics used to make car bodies and cases for computers and other appliances

2. A bachelor's degree in arts and sciences

3. The eleventh month of the civil year; the fifth month of the ecclesiastical year in the Jewish calendar (in July and August)

4. The muscles of the abdomen

5. The blood group whose red cells carry both the A and B antigens