DUMMKOPF is a playable word

dummkopf Scrabble® Dictionary

noun
pl. dummkopfs
a dolt
40 Playable Words can be made from "DUMMKOPF"
   2-Letter Words (12 found)
   3-Letter Words (21 found)
   4-Letter Words (6 found)
   8-Letter Words (1 found)