There are 13 words that end with 'htness'.
| lightness | rightness |
| tightness | brightness |
| slightness | uprightness |
| uptightness | airtightness |
| gastightness | straightness |
| downrightness | forthrightness |
| watertightness | |
Note: These 13 words that end with 'htness' are found from the USA & Canada version of the tournament Scrabble word list.