diffuse

1 of 2

adjective

dif·​fuse di-ˈfyüs How to pronounce diffuse (audio)
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 How to pronounce diffuse (audio)
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 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 word 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 is pain that not concentrated or localized, being instead spread throughout a wider area of the body.

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 See More
Recent Examples on the Web
Adjective
In large companies with diffuse corporate hierarchies, that legal bar can be difficult to meet. Richard Vanderford, WSJ, 30 Mar. 2023 The researchers’ findings, published this week in the scientific journal Nature Genetics, associate lower alcohol tolerance with higher risk of diffuse stomach cancer, a rarer type of gastric cancer that affects more than one area of the stomach. Angela Yang, NBC News, 17 Mar. 2023 The red regions toward the top of this image are areas where dust clouds are relatively diffuse. Jake Parks, Discover Magazine, 11 Nov. 2022 Dragonfly 44 and its ilk are known as ultra-diffuse galaxies (UDGs). Lyndie Chiou, Quanta Magazine, 7 Nov. 2022 First, there are two ultra-diffuse galaxies that appear to be satellite members of a massive group dominated by NGC 1052: DF2 and DF4. Ethan Siegel, Forbes, 22 June 2021 In Los Angeles County, the impacts of the pandemic have been relatively diffuse, with millions of residents suffering and grieving in isolation across a famously vast sprawl. Matthew Bloch, New York Times, 29 Jan. 2021 In large part, that’s because the CO2 in power plant emissions is relatively diffuse. Tim McDonnell, Quartz, 13 Aug. 2020 Kraftwerk’s studio albums have been sampled liberally (by Jay-Z, Afrika Bambaataa, Coldplay), but its influence feels even more diffuse and profound. Amanda Petrusich, The New Yorker, 6 May 2020
Verb
Fortunately, however diffuse the story is, the other stuff happening is frequently delightful, starting with the animation provided by Science Saru and directed by Abel Góngora. Daniel Fienberg, The Hollywood Reporter, 17 Nov. 2023 For mattress pads, which are usually thinner and made of fabric, anything cotton or bamboo is a pretty safe bet for diffusing heat and staying breathable. Olivia Avitt, Peoplemag, 6 Oct. 2023 Blink is back together, the result of a harsh wake-up call that came after Hoppus was diagnosed with stage IV diffuse large B-cell lymphoma in 2021. Amy Kaufman, Los Angeles Times, 29 Oct. 2023 The venue contains a restaurant, a library and a showroom, and the company designed three scents that are diffused in different spaces. T.m. Brown, New York Times, 20 Oct. 2023 And so Reed’s influence as both a figurehead and a solo act diffused across generations—through Patti Smith, Television, Talking Heads, and the New York Dolls, on through to Sonic Youth and R.E.M. and the Cowboy Junkies, to, more recently, the Killers and (most self-consciously) the Strokes. Jeremy Lybarger, The New Republic, 17 Oct. 2023 The end result is a functional piece that makes a serious statement (a tea light candle warms the oil burner, and then diffuses the scent into the space). Christian Allaire, Vogue, 22 Aug. 2023 And, this spray doesn’t have that unpleasant odor many other bug repellents do but instead diffuses a citrus-vanilla scent. Jenna Clark, Southern Living, 20 Oct. 2023 This 1952 theory predicted that recognizable patterns in nature may appear spontaneously when chemicals within the objects or organisms diffuse and then react together. Laura Baisas, Popular Science, 27 Sep. 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'diffuse.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

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

Time Traveler
The first known use of diffuse was in the 15th century

Dictionary Entries Near diffuse

Cite this Entry

“Diffuse.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/diffuse. Accessed 30 Nov. 2023.

Kids Definition

diffuse

1 of 2 adjective
dif·​fuse dif-ˈyüs How to pronounce diffuse (audio)
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 How to pronounce diffuse (audio)
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 How to pronounce diffuse (audio)
: not concentrated or localized
diffuse sclerosis

diffuse

2 of 2 verb
dif·​fuse dif-ˈyüz How to pronounce diffuse (audio)
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

More from Merriam-Webster on diffuse

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