VASTEST is a playable word

vast Scrabble® Dictionary

adjective
vaster, vastest
of great extent or size
noun
pl. vasts
a vast space
88 Playable Words can be made from "VASTEST"
   2-Letter Words (7 found)
   3-Letter Words (24 found)
   6-Letter Words (5 found)
   7-Letter Words (1 found)