thickwit
/ˈθɪk.wɪt/Definitions
1. noun
A stupid or foolish person, especially one who is obstinately ignorant or obstinately obstinate.
“He was called a thickwit for refusing to accept the obvious explanation.”
2. verb
to speak or act like a thickwit
“After watching the absurd movie, he thickwittedly started to make fun of the characters.”