Yes, driest is a Scrabble word!

Adjective

1. Free from liquid or moisture; lacking natural or normal moisture or depleted of water; or no longer wet

2. Humorously sarcastic or mocking

3. Lacking moisture or volatile components

4. Opposed to or prohibiting the production and sale of alcoholic beverages

5. Not producing milk

6. (of liquor) having a low residual sugar content because of decomposition of sugar during fermentation

7. Without a mucous or watery discharge; a small child with a dry nose"

8. Not shedding tears

9. Lacking interest or stimulation; dull and lifeless

10. Used of solid substances in contrast with liquid ones

11. Unproductive especially of the expected results

12. Having no adornment or coloration

13. (of food) eaten without a spread or sauce or other garnish

14. Having a large proportion of strong liquor

15. Lacking warmth or emotional involvement

16. Practicing complete abstinence from alcoholic beverages; I happen to be teetotal"