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Synonyms

brainless

American  
[breyn-lis] / ˈbreɪn lɪs /

adjective

  1. mentally weak; foolish; witless; stupid.

brainless British  
/ ˈbreɪnlɪs /

adjective

  1. stupid or foolish

"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

  • brainlessly adverb
  • brainlessness noun

Etymology

Origin of brainless

First recorded in 1400–50, brainless is from the late Middle English word braynles. See brain, -less

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.

Why do we love this story so much, enough to subject ourselves to even the weirdest, most brainless versions of it that can be spun from the public domain?

From Salon • Dec. 24, 2025

A stunned England woke Sunday to savage criticism after their meek capitulation in the first Ashes Test, branded "brainless" and "damaged" by former greats after their cavalier approach backfired.

From Barron's • Nov. 23, 2025

Meme coins spawned on sites like Pump.fun, where the awful and the brainless alike became speculative fodder.

From The Wall Street Journal • Nov. 21, 2025

The Spectator described the show as "brainless", suggesting Winkleman "gushed" over her guests and asked obvious questions.

From BBC • Nov. 8, 2025

Penelope replied: “He is no fool; he sees how it could be. Never were mortal men like these for bullying and brainless arrogance!”

From "The Odyssey" by Homer

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.