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

• airheaded
• birdbrained
• bonehead
• boneheaded
• brain-dead
• bubbleheaded
• chuckleheaded
• dense
• dim
• dim-witted
• doltish
• dopey
• dopy
• dorky [slang]
• dull
• dumb
• dunderheaded
• empty-headed
• fatuous
• gormless [chiefly British]
• half-witted
• knuckleheaded
• lamebrain
• lamebrained
• lunkheaded
• mindless
• oafish
• obtuse
• opaque
• pinheaded
• senseless
• simple
• slow
• slow-witted
• soft
• softheaded
• stupid
• thick
• thick-witted
• thickheaded
• unintelligent
• unsmart
• vacuous
• weak-minded
• witless

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

The O’Haras happen to move in next door to him. Frothy and often filthy without being brainless (send thanks across the Atlantic for that good British dialogue), this is escapism done right. —Judy Berman, TIME, 30 Oct. 2024

So, what can the neuronal activity of a tiny, brainless creature possibly tell us about the evolution of our own complex brains? —Elizabeth Rayne, Ars Technica, 15 June 2024

There's really no way to prep for the show — basically, just don't be brainless. —Tanner Stransky, EW.com, 8 Apr. 2024

An oyster, immobile and nearly brainless, is hardly even an animal, despite what the taxonomists tell us. —Peter Rubin, Longreads, 9 Jan. 2024

Word History

First Known Use

15th century, in the meaning defined at sense 1

Kids Definition

brainless

adjective

brain·​less ˈbrān-ləs 

: lacking intelligence

brainlessly adverb