Yes, just is a Scrabble word!

Adverb

1. And nothing more

2. Indicating exactness or preciseness

3. Only a moment ago

4. Absolutely

5. Only a very short time before

6. Exactly at this moment or the moment described;

Adjective

1. Used especially of what is legally or ethically right or proper or fitting

2. Fair to all parties as dictated by reason and conscience

3. Free from favoritism or self-interest or bias or deception; conforming with established standards or rules

4. Of moral excellence