MUTTER is a playable word

mutter Scrabble® Dictionary

verb
muttered, muttering, mutters
to speak unclearly
31 Playable Words can be made from "MUTTER"
   2-Letter Words (9 found)
   3-Letter Words (12 found)
   4-Letter Words (7 found)
   5-Letter Words (2 found)
   6-Letter Words (1 found)