Is “Dumbest” a Scrabble word?
Yes
DUMBEST
Valid in at least one Scrabble dictionary
Valid in these dictionaries
SOWPODS / CSW
Scrabble UK & International
TWL / NWL
Scrabble North America
Large English Dictionary
General English word list
Meaning of Dumbest
adjective
1.Unable to speak; lacking power of speech (kept in "deaf, dumb, and blind").
“His younger brother was born dumb, and communicated with sign language.”
2.Silent; unaccompanied by words.
“dumb show”
3.(especially of a person) Extremely stupid.
“You are so dumb! You don't even know how to make toast!”
Synonyms: banal, brainless, dopey, ridiculous, silly, stupid