There are 11 15-letter words that end with 'onist'.
| antiabortionist | assimilationist |
| colonizationist | conservationist |
| constructionist | emancipationist |
| insurrectionist | interventionist |
| preformationist | preservationist |
| resurrectionist | |
Note: These 11 15-letter words that end with 'onist' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words end with ionist, gonist, honist, monist, oonist, bonist, conist, donist, lonist, nonist, ronist, sonist, tonist, yonist.
6-letter words end with 'onist' (1)