There are 7 13-letter words that start with 'thi'.
| thiabendazole | thigmotropism |
| thimblerigged | thimblerigger |
| thinkableness | thioridazines |
| thirstinesses | |
Note: These 7 13-letter words that start with 'thi' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with thin, thir, thio, thic, thia, thim, thie, thig, this, thit, thix, thil.
4-letter words start with 'thi' (4)