There are 14 words that start with 'thermi'.
| thermic | thermit | thermion |
| thermite | thermits | thermidor |
| thermions | thermites | thermidors |
| thermionic | thermistor | thermically |
| thermionics | thermistors | |
Note: These 14 words that start with 'thermi' are found from the USA & Canada version of the tournament Scrabble word list.