Words that mean the same thing as useless?

Here are some words with a similar meaning to "useless":

1. Worthless

2. Futile

3. Ineffective

4. Insufficient

5. Inadequate

6. Impotent

7. Insignificant

8. Inconsequential

9. Trivial

10. Null

11. Null and void

12. Redundant

13. Superfluous

14. Unnecessary

15. Unproductive

16. Vain