There are 16 words that start with 'treas'.
| treason | treasons |
| treasure | treasury |
| treasured | treasurer |
| treasures | treasonous |
| treasurers | treasuries |
| treasuring | treasonable |
| treasonably | treasurable |
| treasurership | treasurerships |
Note: These 16 words that start with 'treas' are found from the USA & Canada version of the tournament Scrabble word list.