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Synonyms

brainy

American  
[brey-nee] / ˈbreɪ ni /

adjective

Informal.
brainier, brainiest

  1. intelligent; clever; intellectual.

brainy British  
/ ˈbreɪnɪ /

adjective

  1. informal clever; intelligent

"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

Other Word Forms

  • brainily adverb
  • braininess noun

Etymology

Origin of brainy

First recorded in 1835–45; brain + -y 1

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.

The ad, titled “Good Will Dunkin’,” featured Affleck as the original brainy Boston math whiz, who happens to work at Dunkin’ and arranges a display of Munchkins in a Fibonacci sequence.

From The Wall Street Journal • Feb. 9, 2026

Sir Stephen Fry lived up to his brainy reputation over breakfast, by predicting the chessboard was back: "I could be a knight - oh, I already am," he joked.

From BBC • Oct. 23, 2025

In a bright, charismatic performance, McCalla’s Elinor brings to life the character’s brainy charm and self-possession.

From Los Angeles Times • Apr. 14, 2025

With its blend of culinary history, intense challenges and playful banter, “Clash of the Cookbooks” feels like comfort viewing with a brainy twist, perfect to binge over the holiday break.

From Salon • Dec. 25, 2024

He didn’t believe in brainy Martians, though he recognized the premise of a winning story.

From "Spooked!" by Gail Jarrow

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

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.