There are 16 11-letter words that end with 'tness'.
| ancientness | currentness | distantness |
| compactness | correctness | corruptness |
| earnestness | inexactness | instantness |
| piquantness | perfectness | presentness |
| unquietness | uprightness | uptightness |
| valiantness | ||
Note: These 16 11-letter words that end with 'tness' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words end with ntness, ctness, rtness, stness, htness, itness, etness, ptness, atness, ftness, utness, ltness, otness.
7-letter words end with 'tness' (7)