SWELLEST is a playable word

swell Scrabble® Dictionary

adjective
sweller, swellest
stylish
verb
swelled, swollen, swelling, swells
to increase in size or volume
85 Playable Words can be made from "SWELLEST"
   2-Letter Words (6 found)
   3-Letter Words (19 found)
   6-Letter Words (6 found)
   8-Letter Words (1 found)