SLOWNESSES is a playable word

slowness Scrabble® Dictionary

noun
pl. slownesses
the state of being slow
152 Playable Words can be made from "SLOWNESSES"
   2-Letter Words (14 found)
   6-Letter Words (9 found)
   7-Letter Words (6 found)
   8-Letter Words (5 found)
   9-Letter Words (1 found)
   10-Letter Words (1 found)