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brainiac

American  
[brey-nee-ak] / ˈbreɪ niˌæk /

noun

  1. a highly intelligent person.


brainiac British  
/ ˈbreɪnɪˌæk /

noun

  1. 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.

See Examples For:

Who knows what might have happened if an ordinary pol like Harding, rather than the zealous brainiac Hoover, had been president in 1929.

From The Wall Street Journal Jun. 17, 2026

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

Guiding his efforts in this second season, along with Owen Wilson’s Mobius, is Ke Huy Quan’s Ouroboros, the nerdy brainiac running the TVA’s Repairs and Advancement Department.

From Salon Nov. 9, 2023

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

I saw Annabeth playing trivia games and other brainiac stuff.

From "The Lightning Thief" by Rick Riordan

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