STRAIGHTEST is a playable word

straight Scrabble® Dictionary

adjective
straighter, straightest
extending uniformly in one direction without bends or irregularities
verb
straighted, straighting, straights
to make straight
606 Playable Words can be made from "STRAIGHTEST"
   2-Letter Words (23 found)
   3-Letter Words (83 found)
   9-Letter Words (3 found)
   10-Letter Words (1 found)
   11-Letter Words (1 found)