dense

adjective

ˈden(t)s 

denser; densest

1

a

: marked by compactness or crowding together of parts

dense vegetation

dense traffic

b

chemistry : having a high mass (see mass entry 2 sense 1c) per unit volume (see volume entry 1 sense 2)

Carbon dioxide is a dense gas.

The cake was overly sweet and dense.

2

a

: slow to understand : stupid, thickheaded

was too dense to get the joke

b

: extreme

dense ignorance

3

mathematics : having between any two elements at least one element

The set of rational numbers is dense.

4

: demanding concentration to follow or comprehend

dense prose

5

: having high or relatively high opacity (see opacity sense 2)

a dense fog

a dense photographic negative

densely adverb

denseness

ˈden(t)-snəs 

noun

Synonyms

• crowded
• thick
• packed
• tight
• compact

Choose the Right Synonym for dense

stupid, dull, dense, crass, dumb mean lacking in power to absorb ideas or impressions.

stupid implies a slow-witted or dazed state of mind that may be either congenital or temporary.

stupid students just keeping the seats warm

stupid with drink

dull suggests a slow or sluggish mind such as results from disease, depression, or shock.

monotonous work that leaves the mind dull

dense implies a thickheaded imperviousness to ideas.

too dense to take a hint

crass suggests a grossness of mind precluding discrimination or delicacy.

a crass, materialistic people

dumb applies to an exasperating obtuseness or lack of comprehension.

too dumb to figure out what's going on

Examples of dense in a Sentence

They cut a path through the dense jungle.

a dense tangle of wires

a dense cluster of stars

That part of the city has a dense population of immigrants.

A dense mass of spectators filled the courtroom.

In the movie, she plays his kind but somewhat dense aunt.

Recent Examples on the Web

Where the Earth has a dense atmosphere, abundant water and life, Mars is a desiccated, lifeless world where even the prospects of finding fossil bacteria are a long shot. —New Atlas, 12 July 2025

In the photo, the orange-brown tiers represent stardust, while small patches represent seemingly vacant zones that indicate the presence of dense foreground filaments of dust that are home to still-forming stars, astronomers said. —Julia Jacobo, ABC News, 11 July 2025

On Friday at 6:54 a.m. a dense fog advisory was issued by the NWS Blacksburg VA in effect until 9 a.m. —Nc Weather Bot, Charlotte Observer, 11 July 2025

Then there’s the Marine North Berwick, Scotland, surrounded by arguably the densest concentration of standout courses on earth, including two in the World Top 10. —Larry Olmsted, Forbes.com, 10 July 2025

Word History

Etymology

Latin densus; akin to Greek dasys thick with hair or leaves

First Known Use

15th century, in the meaning defined at sense 1a

Rhymes for dense

• cense
• fence
• hence
• lense
• mense
• sense
• tense
• thence
• whence
• antisense
• commonsense
• effulgence

Kids Definition

dense

adjective

ˈden(t)s 

denser; densest

1

a

: marked by closeness or crowding together of parts

a dense forest

b

: having a high mass per unit volume

lead is a very dense metal

2

: slow to understand : stupid sense 1a

3

: thick entry 1 sense 4

dense fog

4

: having between any two mathematical elements at least one element

the set of rational numbers is dense

densely adverb

denseness noun