There are 11 words that end with 'onious'.
| felonious | harmonious |
| euphonious | acrimonious |
| ceremonious | symphonious |
| inharmonious | parsimonious |
| disharmonious | sanctimonious |
| unceremonious | |
Note: These 11 words that end with 'onious' are found from the USA & Canada version of the tournament Scrabble word list.