diffuse

1 of 2

adjective

dif·​fuse di-ˈfyüs 

1

: being at once verbose and ill-organized

a diffuse report from the scene of the earthquake

2

: not concentrated or localized

diffuse lighting

diffuse sclerosis

diffusely adverb

diffuseness noun

diffuse

2 of 2

verb

dif·​fuse di-ˈfyüz 

diffused; diffusing

transitive verb

1

a

: to pour out and permit or cause to spread freely

a drop of blue dye diffused in a glass of water

b

: extend, scatter

diffusing their ideas throughout the continent

c

: to spread thinly or wastefully

a government in which power is diffused

2

physics : to subject to diffusion (see diffusion sense 3)

especially : to break up and distribute (incident light) by reflection

put up a screen to diffuse the light

intransitive verb

1

: to spread out or become transmitted especially by contact

The civilization diffused westward.

2

: to undergo diffusion

heat from the radiator diffusing throughout the room

diffusible

di-ˈfyü-zə-bəl 

adjective

Frequently Asked Questions

What is the difference between diffuse and defuse?

Many people find it difficult to remember the difference between defuse and diffuse, and when faced with the need for one of these words simply grab whichever one first comes to mind. Although these words sound quite similar, their meanings are rather distinct. Defuse means "to make less harmful, potent, or tense"; the word has another, helpfully literal, meaning, which is "to remove the fuse from." Diffuse means "not concentrated or localized"; it comes from the Latin word diffūsus ("spread over a wide area").

What is the difference between diffuse and infuse?

Diffuse is commonly found used as both adjective ("not concentrated or localized") and verb ("to pour out and permit or cause to spread freely," "to scatter"), while infuse is almost entirely restricted to use as a verb. While the meannings of diffuse are mainly concerned with outward movement, those of infuse are inward; the word has such meanings as "to steep in liquid (such as water) without boiling so as to extract the soluble constituents or principles," "to administer or inject by infusion," and "to cause to be permeated with something (such as a principle or quality) that alters usually for the better."

What does diffuse pain mean?

Diffuse pain is pain that is not concentrated or localized, being instead spread throughout a wider area of the body.

Synonyms

Adjective

• circuitous
• circumlocutory
• garrulous
• logorrheic
• long-winded
• pleonastic
• prolix
• rambling
• verbose
• windy
• wordy

Choose the Right Synonym for diffuse

wordy, verbose, prolix, diffuse mean using more words than necessary to express thought.

wordy may also imply loquaciousness or garrulity.

a wordy speech

verbose suggests a resulting dullness, obscurity, or lack of incisiveness or precision.

the verbose position papers

prolix suggests unreasonable and tedious dwelling on details.

habitually transformed brief anecdotes into prolix sagas

diffuse stresses lack of compactness and pointedness of style.

diffuse memoirs that are so many shaggy-dog stories

Examples of diffuse in a Sentence

Adjective

The forest was filled with a soft, diffuse light.

a diffuse speech that took a great deal of time to make a very small point

Verb

The heat from the radiator diffuses throughout the room.

The heat was diffused throughout the room.

The photographer uses a screen to diffuse the light.

an area of diffused light

Recent Examples on the Web

Adjective

The large-scale cloud formations visible in the foreground belong to our own Milky Way galaxy, as do the several distinct colorful stars which surround the diffuse spiral shape of M31. —Miguel Claro, Space.com, 23 Apr. 2025

Cultural attitudes on each side toward consumer safety, environmental protection, and privacy run deep, and they will not be overcome with promises of diffuse economic benefits and future job growth. —Thomas J. Bollyky, Foreign Affairs, 10 July 2013

Verb

The world isn’t safer if power is diffused away from the American center and countries seek to fill the void within their various spheres of influence. —Colin Pascal, Baltimore Sun, 1 May 2025

Like an epic poem told through a multitude of voices, Miguel Gomes’s Grand Tour is a movie of unorthodox sweep and diffuse grace. —Bilge Ebiri, Vulture, 28 Mar. 2025

Word History

Etymology

Adjective

Middle English, "dispersed, verbose (of speech or writing)," borrowed from Middle French & Latin; Middle French diffus, borrowed from Latin diffūsus "spread over a wide area, (of writing) extensive, verbose," from past participle of diffundere "to pour out over a wide surface, spread, extend, squander" — more at diffuse entry 2

Verb

Middle English, in past participle diffusid, borrowed from Latin diffūsus, past participle of diffundere "to pour out over a wide surface, spread out, extend, squander," from dif-, assimilated form of dis- dis- + fundere "to pour, shed" — more at found entry 5

First Known Use

Adjective

1612, in the meaning defined at sense 1

Verb

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

Phrases Containing diffuse

• diffuse-porous

Rhymes for diffuse

• abstruse
• abuse
• adduce
• atreus
• caboose
• cayuse
• conduce
• deduce
• disuse
• excuse
• footloose
• induce

Kids Definition

diffuse

1 of 2 adjective

dif·​fuse dif-ˈyüs 

1

: using too many words : verbose

a diffuse writer

2

: poured or spread out : not concentrated

diffuse daylight

diffusely adverb

diffuseness noun

diffuse

2 of 2 verb

dif·​fuse dif-ˈyüz 

diffused; diffusing

1

: to pour out and permit or cause to spread freely

2

: to go through or cause to go through diffusion

Medical Definition

diffuse

1 of 2 adjective

dif·​fuse dif-ˈyüs 

: not concentrated or localized

diffuse sclerosis

diffuse

2 of 2 verb

dif·​fuse dif-ˈyüz 

diffused; diffusing

transitive verb

1

: to subject (as a light beam) to diffusion

2

: to break up and distribute (incident light) by reflection (as from a rough surface)

intransitive verb

: to undergo diffusion