Yes, shabby is in the scrabble dictionary

...and is worth 16 points by itself if you played it.

Shabby Definition

adjective

Despicable; mean: a shabby trick.
Dilapidated or deteriorated in condition, especially through neglect; seedy: a shabby little park.
Not generous or just; unfair: shabby treatment.
Of mediocre or substandard quality: a shabby performance.
Showing signs of wear and tear; threadbare or worn-out: shabby furniture.