nounNorth American informal
An exceptionally intelligent person: she’s the original brainiac, a kid who completed high school at 14
More example sentences
- Can you please tell the brainiacs and intellectuals that not everyone is a walking dictionary?
- I'll tell you what, you goddamn egghead brainiacs at NASA: I don't want a space elevator.
- Here's what the brainiacs on the editorial board of The World's Greatest Newspaper can't understand.
Definition of brainiac in:
- The US English dictionary