There are 19 9-letter words that start with 'ther'.
| therapies | therapist | therapsid |
| therefore | therefrom | thereinto |
| theremins | thereunto | thereupon |
| therewith | theriacal | theriacas |
| thermally | thermidor | thermions |
| thermites | thermoses | thermoset |
| theropods | ||
Note: These 19 9-letter words that start with 'ther' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with therm, there, thera, theri, thero.
5-letter words start with 'ther' (2)