SLOWEST is a playable word

slow Scrabble® Dictionary

adjective
slower, slowest
moving with little speed
verb
slowed, slowing, slows
to lessen the speed of
111 Playable Words can be made from "SLOWEST"
   2-Letter Words (13 found)
   3-Letter Words (29 found)
   6-Letter Words (4 found)
   7-Letter Words (2 found)