brainless

adjective

brain·​less ˈbrān-ləs 

1

: devoid of intelligence : stupid

a brainless decision

2

: not demanding understanding or intelligence : dull, stupefying

a brainless task

brainless repetition

3

: lacking a brain

brainless organisms

brainlessly adverb

brainlessness noun

Synonyms of brainless

• dumb
• stupid
• slow
• simple
• thick
• mindless

Examples of brainless in a Sentence

He thought most of his coworkers were brainless.

The plot of the new movie is brainless and the acting is terrible.

Recent Examples on the Web

Fieryo / Scarecrow The brainless Scarecrow was formerly Fiyero Tigelaar, the most eligible bachelor in Oz. —Haley Kluge, Variety, 22 Nov. 2025

That Malice can be heartless and brainless need not be a problem; some of my favorite shows are mean and stupid, and downright gleeful about it. —Angie Han, HollywoodReporter, 14 Nov. 2025

This extends well beyond the 2025 Bombers, their signature head-scratching and somewhat brainless play on the field has plagued them dating back to 2021. —James O'Connell, New York Daily News, 7 Aug. 2025

There's really no way to prep for the show — basically, just don't be brainless. —Lindsay Soll, EW.com, 25 July 2025

Word History

First Known Use

15th century, in the meaning defined at sense 1

Rhymes for brainless

• painless
• rainless
• stainless

Kids Definition

brainless

adjective

brain·​less ˈbrān-ləs 

: lacking intelligence

brainlessly adverb