Shit-for-brains

Origin

Canadian 1950s.

Full definition of shit-for-brains

Adjective

1. (pejorative, vulgar slang) Extremely stupid.That shit-for-brains assistant of mine lost my files again.
• 2005, In Her Shoes (2005 film) (film):Who are you crying about, the predatory prick or the shit-for-brains tramp? Because neither one deserves your tears.

Noun

1. (vulgar slang) An extremely stupid person.That new assistant of yours is a real shit-for-brains.He's another one of those shit-for-brains.