There are 152 10-letter words that end with 'iest'.
Note: These 152 10-letter words that end with 'iest' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words end with liest, tiest, kiest, hiest, piest, giest, riest, siest, diest, niest, miest, ziest, biest, fiest, ciest, wiest, viest, xiest, oiest, uiest, yiest.
6-letter words end with 'iest' (7)