talk that's pompous and attempting to appear intelligent.
Everything that professor says is brainiac yack.
A stupid person who thinks he or she is smart.
Sam: I thought oil would smother the flames of the fire.
Dave: Way ta go, shit-for-brainiac
When someone gives such good head your brain implodes
Leo likes when Donnie gives good brainiac
A dc super villain how wants to steal all knowledge and is also called the smartest being in the universe
Superman: I will stop brainiac
A Brainiac is a person who wears spectacles and has a piercing in the gay ear
"Look that guy has spectacles and a piercing in his gay ear!. He must be a brainiac, I hope I don't have monkeypox off him"