DUMFOUNDING is a playable word

dumfound Scrabble® Dictionary

verb
dumfounded, dumfounding, dumfounds
to astonish
131 Playable Words can be made from "DUMFOUNDING"
   2-Letter Words (18 found)
   6-Letter Words (7 found)
   7-Letter Words (8 found)
   8-Letter Words (5 found)
   11-Letter Words (1 found)