There are 3 15-letter words that end with 'oning'.
| decommissioning | recommissioning |
| preconditioning | |
Note: These 3 15-letter words that end with 'oning' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words end with ioning, ooning, soning, toning, roning, honing, poning, boning, eoning, doning, goning, zoning, koning, coning, moning, loning, noning, yoning.
6-letter words end with 'oning' (5)