BUTTERIEST is a playable word

buttery Scrabble® Dictionary

adjective
butterier, butteriest
containing butter
noun
pl. butteries
a wine cellar
260 Playable Words can be made from "BUTTERIEST"
   2-Letter Words (13 found)
   8-Letter Words (3 found)
   9-Letter Words (3 found)
   10-Letter Words (1 found)