dumbhead

/ˈdʌmˌhɛd/
noun
  1. A person who is considered stupid or slow to understand; a foolish person.
    • Don't be a dumbhead—check your work before handing it in.
    • He called me a dumbhead for forgetting my keys again.
    • Only a dumbhead would try to cross the street without looking.
Antonyms
What does "dumbhead" mean? | whatsthatwordmean | whatsthatwordmean