dumbitious
Trying your hardest to be or appear dumb, whether intentionally or unintentionally.
Liam: I hear someone said they has an IQ of 175 from an internet IQ test.
Josh: He's so dumbitious.
Josh: He's so dumbitious.
dumbity
A term or street slang used to describe stupidity.
I lost my wallet because of my dumbity.
dumbitis
A disease in to where a person is diagnosed with the dumb
Im sorry ma’am, your son suffers from dumbitis