GLUM is a playable word

glum Scrabble® Dictionary

noun
pl. glums
glumness
adjective
glummer, glummest
being in low spirits
(adverb) glumly
8 Playable Words can be made from "GLUM"
   2-Letter Words (2 found)
   3-Letter Words (5 found)
   4-Letter Words (1 found)