A knucklehead is a person who is very stupid or foolish. They are often the target of jokes, and people often call them names that are associated with stupidity.
He is a knucklehead for driving under the influence.
She is a knucklehead for wearing that dress to the party.
noun
a stupid person; these words are used to express a low opinion of someone's intelligence
Synonyms:
1
If you're an admin, don't be a knucklehead.
2
I guess one is always a knucklehead in training.
3
I deleted it once, but some knucklehead put it back.
4
It used a version of the Knucklehead OHV engine that powered the EL in form.
5
I would be a knucklehead to trust you without looking at sources, however.
6
Please state for the record whether you are at all related to Knucklehead Zoo.