Yes, poor is a Scrabble word!
...and is worth 6 points in Scrabble, and 7 points in Words with Friends
poor
Adjective
1. Deserving or inciting pity
2. Having little money or few possessions
3. Characterized by or indicating poverty
4. Lacking in specific resources, qualities or substances
5. Not sufficient to meet a need
6. Unsatisfactory
Noun
1. People without possessions or wealth (considered as a group)
What Scrabble words can I make with the letters in poor?
3 Letter Words
2 Letter Words