diffuse

adjective
dif·​fuse | \ di-ˈfyüs How to pronounce diffuse (audio) \

Definition of diffuse

 (Entry 1 of 2)

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

diffuse

verb
dif·​fuse | \ di-ˈfyüz How to pronounce diffuse (audio) \
diffused; diffusing

Definition of diffuse (Entry 2 of 2)

transitive verb

1a : 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

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Other Words from diffuse

Adjective

diffusely adverb
diffuseness noun

Verb

diffusible \ di-​ˈfyü-​zə-​bəl How to pronounce diffusible (audio) \ adjective

Choose the Right Synonym for diffuse

Adjective

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

defuse or diffuse?

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. But it needn’t be this way: the meanings of these two are quite a bit different, and there is a simple way to differentiate between them. Defuse is formed by adding the prefix de- to the word fuse; you are removing the fuse (either literally or figuratively) when you defuse a situation, much as defanging something entails removing the fangs. Diffuse, when used as a verb, tends to carry meanings such as “spread” or “scatter.” Additionally, diffuse is the only one which may be found used as an adjective.

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
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Recent Examples on the Web: Adjective

Try to be the bigger person, but don’t let self-restraint get you down — diffuse frustrations through something like journaling, taking long walks, or cooking a meal. Randon Rosenbohm, Allure, "What June's Pisces Horoscope Predictions Mean for You," 29 May 2019 The rapid, diffuse arrival of electric scooters on sidewalks and street corners revealed the yawning gaps in urban transportation that cars, buses, trains, and bikes just can’t close. Umair Irfan, Vox, "The scooter stampede of 2018 is great news for urban transportation," 5 Dec. 2018 Photo: Piroschka van de Wouw/Reuters A proliferation in mergers and a more global approach to banking has produced diffuse headquarters in that sector. Te-ping Chen, WSJ, "Lessons for Amazon in Running Multiple Headquarters," 5 Nov. 2018 Runner’s knee can feel like a dull, diffuse ache in and around the kneecap. SELF, "How to Know When It’s Safe to Run Through Knee Pain and When You Need to Stop," 7 Dec. 2018 Clint Watts, a senior fellow with the Foreign Policy Research Institute, said the diffuse nature of congressional and state races makes them a harder target than a single presidential election. Robert Mcmillan, WSJ, "Russian Hackers Largely Skipped the Midterms, and No One Really Knows Why," 12 Nov. 2018 The earlier data, from day 75, showed radio emissions that were relatively diffuse. John Timmer, Ars Technica, "Neutron-star merger blasted a jet of material through the debris," 5 Sep. 2018 The front is somewhat diffuse, shallow and does not have great impetus to move. Jeff Halverson, Washington Post, "Heavy showers and storms may target Washington region around sunset," 20 June 2018 But as the war has dragged on, growing more diffuse and complex, many international monitoring groups have essentially stopped counting. Megan Specia, New York Times, "How Syria’s Death Toll Is Lost in the Fog of War," 13 Apr. 2018

Recent Examples on the Web: Verb

While not every company has caught up to this idea, more and more offices are becoming pet-friendly in an effort to increase workplace morale and diffuse stress. Kelli Bender, PEOPLE.com, "Want to Bring Your Dog to Work? These Are America's Most Pet-Friendly Companies of 2019," 6 June 2019 Phages are much bigger than antibiotics and won't simply diffuse to the site of an infection. John Timmer, Ars Technica, "Using a virus to kill what antibiotics can’t," 18 July 2018 Clearly there are no diffusing morphogens at work there. Jennifer Ouellette, Quanta Magazine, "Biologists Home In on Turing Patterns," 25 Mar. 2013 This fabulous style Keys is wearing so well was prepped by stylist Jawara with a good blow-dry and then diffused courtesy of the Dyson Supersonic hair dryer professional edition ($400). Maya Allen, Marie Claire, "Alicia Keys Stuck to Wearing Barely Any Makeup at the 2019 Met Gala and Looks Stunning," 7 May 2019 It's apparently packed with emollients like olive extract, as well as light-diffusing powders that create that an incredible airbrushed effect. Glamour, "This Bobbi Brown Foundation Stick Makes My Face Look Instantly Poreless," 8 Mar. 2019 Start with a discreet, less grandiose overhead fixture—say, a pendant light with an alabaster globe that diffuses the glare. Kathryn O’shea-evans, WSJ, "Goodbye, Showy Chandeliers. Hello, Low-Key Lighting That Transforms Rooms," 25 Jan. 2019 Apply lipstick in the same fashion, then use a lip brush to slightly diffuse the edges for a softer look. Lauren Valenti, Vogue, "A Guide to Ageless Makeup for Women Over 50, According to an Industry Veteran," 27 Mar. 2019 For 25-year-old beloved K-pop star Taemin, sooty black shadow diffused on the outer corners of his lids has helped emphasize his signature duality. Devon Abelman, Allure, "Why Taemin Won't Apologize For His Androgynous Aesthetic Anymore," 15 Mar. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'diffuse.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of diffuse

Adjective

1612, in the meaning defined at sense 1

Verb

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

History and Etymology for diffuse

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

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Learn More about diffuse

Statistics for diffuse

Last Updated

4 Jun 2019

Look-up Popularity

Time Traveler for diffuse

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

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More Definitions for diffuse

diffuse

adjective

English Language Learners Definition of diffuse

 (Entry 1 of 2)

: spread out over a large space : not concentrated in one area

diffuse

verb

English Language Learners Definition of diffuse (Entry 2 of 2)

: to spread out : to move freely throughout a large area
: to exist or be known throughout an area
: to cause (light) to be soft and spread out

diffuse

verb
dif·​fuse | \ di-ˈfyüz How to pronounce diffuse (audio) \
diffused; diffusing

Kids Definition of diffuse

: to spread or allow to spread freely The frosted window diffused the sunlight.

diffuse

adjective
dif·​fuse | \ dif-ˈyüs How to pronounce diffuse (audio) \

Medical Definition of diffuse

 (Entry 1 of 2)

: not concentrated or localized diffuse sclerosis

diffuse

verb
dif·​fuse | \ dif-ˈyüz How to pronounce diffuse (audio) \
diffused; diffusing

Medical Definition of diffuse (Entry 2 of 2)

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

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More from Merriam-Webster on diffuse

Rhyming Dictionary: Words that rhyme with diffuse

Thesaurus: All synonyms and antonyms for diffuse

Spanish Central: Translation of diffuse

Nglish: Translation of diffuse for Spanish Speakers

Britannica English: Translation of diffuse for Arabic Speakers

Comments on diffuse

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