A Dimnut is someone who can either be stupid or someone who doesn't listen.
Dimnut can also be used as a derogatory term, replacing words like Cunt

Anatidaephobia is defined as a pervasive, irrational fear that one is being watched by a duck. The anatidaephobic individual fears that no matter where they are or what they are doing, a duck watches.

Anatidaephobia is derived from the Greek word "anatidae", meaning ducks, geese or swans and "phobos" meaning fear.

An unintelligent child, that has the brain the size of a peanut or small

A crazy person who is also not very bright