There are 11 15-letter words that end with 'ogist'.
| biotechnologist | chronobiologist |
| cryptozoologist | endocrinologist |
| geochronologist | geomorphologist |
| roentgenologist | phenomenologist |
| sedimentologist | ophthalmologist |
| psychobiologist | |
Note: These 11 15-letter words that end with 'ogist' are found from the USA & Canada version of the tournament Scrabble word list.