Showing results for brainiac. Search instead for brainiacs.

brainiac

American

[brey-nee-ak] / ˈbreɪ niˌæk /

noun

a highly intelligent person.

brainiac British

/ ˈbreɪnɪˌæk /

noun

informal a highly intelligent person

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of brainiac

From Brainiac, a superintelligent, villainous alien in the Superman comics, probably brain + (man)iac

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Living up to his reputation as Cahiers’ brainiac bad boy, he pockets the office’s petty cash to road-trip to the Cannes premiere of Truffaut’s “The 400 Blows.”

From Los Angeles Times • Oct. 29, 2025

Over countless tweets, interviews and TV appearances, he’s positioned himself as a mad-scientist-cum-diplomat — a straight-talking brainiac willing to embrace regulation of his nascent industry and criticize its worst excesses.

From New York Times • May 14, 2022

"Big Bang Theory" real-life brainiac Mayim Bialik was excellent.

From Salon • Aug. 6, 2021

Saying the NFL is America’s most popular sport isn’t exactly brainiac territory.

From Seattle Times • Jul. 23, 2021

“If you’re such a brainiac, how come you never skipped grades?”

From "Made You Up" by Francesca Zappia

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023