DUMBER is a playable word

dumb Scrabble® Dictionary

adjective
dumber, dumbest
lacking intelligence
verb
dumbed, dumbing, dumbs
to make silent
48 Playable Words can be made from "DUMBER"
   2-Letter Words (9 found)
   3-Letter Words (19 found)
   4-Letter Words (13 found)
   5-Letter Words (6 found)
   6-Letter Words (1 found)