COMPLETEST is a playable word

complete Scrabble® Dictionary

adjective
completer, completest
having all necessary parts
verb
completed, completing, completes
to bring to an end
335 Playable Words can be made from "COMPLETEST"
   2-Letter Words (16 found)
   8-Letter Words (4 found)
   9-Letter Words (1 found)
   10-Letter Words (1 found)