Yes, grinded is a Scrabble word!

Verb

1. Press or grind with a crushing noise

2. Make a grating or grinding sound by rubbing together

3. Work hard

4. Dance by rotating the pelvis in an erotically suggestive way, often while in contact with one's partner such that the dancers' legs are interlaced

5. Reduce to small pieces or particles by pounding or abrading

6. Created by grinding

7. Shape or form by grinding