There are 6 9-letter words that start with 'therm'.
| thermally | thermidor | thermions |
| thermites | thermoses | thermoset |
Note: These 6 9-letter words that start with 'therm' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with thermo, thermi, therma, therme, therms.
6-letter words start with 'therm' (2)