There are 6 15-letter words that end with 'ning'.
| decommissioning | counterstaining |
| overlengthening | recommissioning |
| preconditioning | restrengthening |
Note: These 6 15-letter words that end with 'ning' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words end with ining, oning, ening, nning, rning, aning, gning, wning, uning, mning, yning, lning, tning.
6-letter words end with 'ning' (22)