There are 15 words that start with 'treat'.
| treat | treats |
| treaty | treated |
| treater | treaters |
| treaties | treating |
| treatise | treatable |
| treatises | treatment |
| treatments | treatability |
| treatabilities | |
Note: These 15 words that start with 'treat' are found from the USA & Canada version of the tournament Scrabble word list.