A portmanteau of garbage and bull or alternatively bullshit
A new word to say how terrible something is or how full of crap it is
Grade 11 Student: Man, I put a lot of effort into that research paper, and i got a 65%? That's total garbull!
Adult: Man, I work way harder than that freeloading prick Jonathan, why does he get the promotion and not me! Urghh this is garbull!!!