Imbecilic, Moronic, Just Plain Dumb
Puzzle 8 of Hand Sports Medium Pack
Question is: Imbecilic, Moronic, Just Plain Dumb
and the answer is: IDIOTIC
Word Meaning:
IDIOTIC — (of a person or animal) Pertaining to or resembling an idiot; characterised with behaviour resembling idiocy.
Definitions from Wiktionary.